Dictionary of Botanical Terms


Alphabetical Search By Botanical Terms:
A B C D E F G H I J K L M N O P R S T U V W X Y Z

Achene: [Fruits] {type} A more or less small, dry fruit that does not split open at maturity (indehiscent), with a typically thin, close-fitting wall surrounding a single seed.

Acicular: [Leaflets, Leaves] {shape} Very long and slender, gradually tapering to a point, like a needle; needle-shaped.

Acorn: [Fruits] {type} A nut with a persistent, cup-like structure (cupule) attached at the base consisting of numerous partially fused, overlapping, dry bracts, as in oaks (Quercus).

Actinomorphic: radially symmetrical -- used of organisms, organs, or parts capable of division into essentially symmetrical; halves by any longitudinal palne passing through the axis

Acuminate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Gradually tapering to a sharp point, forming concave sides along the tip.

Acute: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Tapering to a pointed apex with more or less straight sides, the sides coming together at an angle of less than 90:.

Adnate: grown together, used especially of unlike parts

Adventitious: (1) Structures or organs arising in a position that is unusual for their type, as roots originating on the stem.

Adventitious: (2) [Roots] {type} Roots arising from any part of the plant (e.g. stem or leaf) other than the root system; usually growing laterally, often from the lower part of the main stem.

Aerial stem: [Stems] {type} A prostrate to erect, above ground stem.

Aggregate: of a flower clustered in a dense mass or head; of a fruit : formed from the several separate or fused ovaries of a single flower

Aggregate fruit: [Fruits] {type} A cluster of fruits that stick together or are fused, originating from two or more separate pistils contained within a single flower, as in jackfruity (Artocarpus).

Alternate: [Leaves] {insertion} Positioned singly at different heights on the stem; one leaf occurring at each node.

Ament: an indeterminate spicate inflorescence bearing scaly bracts and apetalous unisexual flowers (as in the willow)

Androecium: A collective term for all the stamens and any closely associated structures in a flower.

Angiosperm: [Plants] {major group} Plants that bear their seeds enclosed in an ovary; the flowering plants.

Annual: [Plants] {life span} Normally living one year or less; growing, reproducing, and dying within one cycle of seasons.

Anther: The pollen-producing portion of the stamen typically borne at the tip of a stalk or filament.

Anthocarp: a fruit with some portion of the flower besides the pericarp persisting, as in a pome with the fleshy perianth tube surrounding the pericarp (h)

Apex: The portion of a plant structure (such as a leaf, bud, stem, etc.) farthest from its point of attachment or uppermost; the tip.

Apical: [Placentation] {type} Attachment of ovules at the top or apex of the ovary.

Apiculate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Ending abruptly in a small, slender, point that is not stiff and often slightly curved.

Apocarpous: having the carpels of the gynoecium separate

Apopetalous: [Corolla] {fusion} With petals distinct, not fused.

Apophysis: The outer portion of a cone scale which is exposed when the cone is closed.

Aposepalous: [Calyx] {fusion} With sepals distinct, not fused.

Appressed: [Leaves, Petals, Phyllaries, Sepals] {vertical orientation} Pressed upwardly close or flat against the bearing structure, thus more or less parallel to it.

Aquatic-emergent: [Plants] {habit} Growing in water with stem and leaves extending above the surface.

Aquatic-floating: [Plants] {habit} Growing in water with leaves floating on the surface.

Aquatic-submerged: [Plants] {habit} Growing in water with stem and leaves beneath the surface.

Arachnoid: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} With fairly sparse, fine, white, loosely tangled hairs; cobwebby.

Areole: a small pit or cavity (as that from which spines arise in cacti)

Aril: an exterior covering or appendage of certain seeds that develops after fertilization as an outgrowth from the funiculus and envelopes the seed

Aristate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Bearing a prolonged, slender, stiff, usually straight tip; awned or bristled.

Armature: Any kind of sharp defense such as thorns, spines, or prickles.

Armed: (1) [Bark of mature trunks] {surface appearance} Bearing any kind of sharp defense such as thorns, spines, or prickles.

Armed: (2) [Seed cone scales] {armature} Bearing a hook, prickle or other sharply pointed structure on the end of the cone scale.

Ascending: [Leaves, Petals, Phyllaries, Sepals] {vertical orientation} Spreading at the base and then curving upward to an angle of 45: or less relative to the bearing structure.

Astringent: Foliage with a soapy or medicinal aroma because of the presence of saponins and other chemicals.

Asymmetric: (1) [Calyx, Corolla] {symmetry} Not divisible into essentially equal halves along any plane.

Asymmetric: (2) [Seed cones] {symmetry} Not divisible into essentially equal halves along any plane.

Attenuate: [Leaf bases, Leaflet bases] {shape} Tapering gradually to a narrow base.

Auriculate: [Leaf bases, Leaflet bases] {shape} With ear-shaped appendages at the base.

Autotrophic: [Plants] {nutrition} Able to synthesize the nutritive substances an organism needs from the non-living environment; in plants, photosynthetic.

Awl-shaped: [Leaflets, Leaves] {shape} Narrowly triangular and sharply pointed, like an awl.

Awn: A slender, more or less straight and stiff, fine-pointed appendage; may be located at the tip of a leaf or bract and a continuation of the midvein, or comprising the pappus in fruits of the sunflower family (Asteraceae).

Axil: The point of the upper angle formed between the axis of a stem and any part (usually a leaf) arising from it.

Axile: [Placentation] {type} Attachment of ovules at or near the center of a compound ovary which has more than one inner compartment (multilocular), the ovules located on the inner angle formed by the interior partitions (septa).

Axillary: [Buds, Inflorescences, Seed cones] {position} On the stem just above the point of attachment of a leaf (or leaf scar) or branch; borne in the axil of a leaf or branch.

Axis: Any relatively long, continuous, supporting structure that typically bears other organs laterally, and represents the main line of growth and/or symmetry; as a stem that bears leaves or branches, or the rachis of an inflorescence that bears flowers along its length.

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B

Banded: [Leaf lower surface, Leaf upper surface] {color variegation} Transverse, or horizontal, stripes of one color crossing another.

Bark: The outermost layer of a woody stem, usually with one or more corky layers that prevent water loss and protect the inner living tissues from mechanical damage.

Basal: (1) At or very near the base of a plant structure.

Basal: (2) [Leaves] {position} With leaves arising at or near the base of the stem.

Basal: (3) [Placentation] {type} Attachment of ovules at the base of the ovary.

Base: The portion of a plant structure (such as a leaf, bud, stem, etc.) nearest the point of attachment or lowermost; the bottom.

Beak: This is a pointed slender appendage that defines the outer tip of a seedpod; the seedpods of many plant species lack beaks. For Carex spp. (Sedges), this term has a different meaning. The perigynium of a Carex sp. can have a slender beak at its apex to enclose the long style of a female floret, or the perigynium can be nearly beakless when the style of the female floret is quite short.

Berry: [Fruits] {type} A fleshy fruit that does not split open at maturity (indehiscent), with few or more seeds (rarely just one), the seeds without a stony covering; the flesh may be more or less homogenous or with the outer portion more firm or leathery; as grapes (Vitis).

Biconvex: convex on both sides

Biennial [Plants] {life span} Normally living two years; germinating or forming and growing vegetatively during one cycle of seasons, then reproducing sexually and dying during the following one.

Bifoliolate: [Leaves] {complexity form} Compound with two leaflets; two-leafleted or geminate.

Bifurcated: A structure that is divided into two parts along some portion of its length. This often refers to petals that are deeply notched at their tips, as occurs in the flowers of Stellaria spp. (Chickweeds) and Cerastium spp. (Mouse-Eared Chickweed).

Bigeminate: [Leaves] {complexity form} With two orders of leaflets, each divided into pairs or geminately compound; doubly paired.

Bilabiate: having two lips

Bilaterally symmetric: [Calyx, Corolla] {symmetry} Divisible into two essentially equal portions along only one plane.

Bipalmately compound: [Leaves] {complexity form} With two orders of leaflets, eachpalmately compound; twice palmately compound.

Bipinnate: twice pinnate

Bipinnately compound: [Leaves] {complexity form} With two orders of leaflets, each pinnately compound; twice pinnately compound.

Bipinnately lobed: [Leaves] {lobing form} With two orders of leaf lobing, each pinnately lobed; twice pinnately lobed.

Bipinnate-pinnatifid: [Leaves] {complexity form} Twice pinnately compound with pinnatifid leaflets.

Bipinnatifid: A simple leaf or leaflet that is pinnatifid with lobes along its side margins; these lobes are also pinnatifid with secondary lobes along their margins. Some species of ferns have bipinnatifid leaves; the lobes of such leaves are often cleft.

Bisexual: (1) Having functional reproductive structures of both sexes (i.e. male and female) in the same flower or cone.

Bisexual: (2) [Flowers] {gender} Having functional reproductive structures of both sexes (i.e. male and female) in the same flower.

Biternate: [Leaves] {complexity form} With two orders of leaflets, each divided into threes or ternately compound; twice trifoliolate.

Blade: The flat, expanded portion of a leaf, petal, sepal, etc.

Blade-like: [Stipules] {type} Expanded and flattened, as the main portion or blade of a broad leaf.

Blotched: [Leaf lower surface, Leaf upper surface] {color variegation} The color disposed in broad, irregular blotches.

Bordered: [Leaf lower surface, Leaf upper surface] {color variegation} One color is surrounded by an edging of another.

Boreal: of, relating to, or constituting a terrestrial biogeographic division comprising the northern and mountainous parts of the northern hemisphere in which mean temperature during the six hottest weeks does not exceed 64.4o F. and being equiva lent to the Holarctic region exclusive of the Sonoran and Transition zones and corresponding Old World areas

Brachiate: having widely spreading branches arranged in altenating pairs

Bract: A modified, usually reduced leaf, often occurring at the base of a flower or inflorescence.

Bracteole: a small bract; esp one on a floral axis -- called also bractlet

Branch: A division or subdivision of a stem or other axis.

Branchlet: An ultimate branch, i.e. one located at the end of a system of branches; a small Branch.

Bristle: A slender, more or less straight and stiff, fine-pointed appendage; may be located at the tip of a leaf or bract and a continuation of the midvein, or comprising the pappus in fruits of the sunflower family (Asteraceae).

Broadleaf herbaceous: [Plants] {habit} Herbaceous with relatively broad leaves, thus differing from the long, narrow leaves of grasses (Poaceae) and other grass-like plants .

Broad-leaved: [Leaves] {general form} With leaves that are not needle-like or scale-like, but having relatively broad, flat surfaces, as in most deciduous trees such as maples (Acer).

Bud: An immature shoot, either vegetative, floral or both, and often covered by protective scales.

Buffered: in the case of Nymphaeaceae plants are protected from extreme fluctuations in temperature by the slower rate of change in the body of water (nb)

Bulb: [Stems] {type} A short, vertical, usually underground stem with fleshy storage leaves attached, as in onions (Allium cepa).

Bulbets Small bulbs that are produced underground or above ground as an alternative to seeds. Above ground bulbs are produced in the inflorescence and are called "aerial bulbets." Such bulbets are often produced by some Allium spp. (Onions).

Bulrushes A common name that refers to species in the genus Scirpus. Because Scirpus spp. (Bulrushes) are members of the Cyperaceae (Sedge family), they are actually sedges, notwithstanding the common name.

Bundle scar: A small scar within a leaf scar left by a vascular bundle that previously entered the stalk (petiole) or base of the fallen leaf.

Bur: [Fruits] {type} A cypsela or other fruit enclosed in a whorl of dry bracts (involucre) covered with spines or prickles that are often hooked, aiding in their dispersal by animals, as in cocklebur (Xanthium).

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C

C3 Metabolism: Cool-season plants use a C3 metabolism to convert sunlight into carbohydrates using chlorophyll. They often grow best during the spring or fall when the weather is cool and moist. Most forbs and some grasses and sedges have a C3 metabolism. The chemical pathway of C3 metabolism is slightly different from that of C4 metabolism (see the description below).

C4 Metabolism: Warm-season plants use a C4 metabolism to convert sunlight into carbohydrates using chlorophyll. These plants often grow best during the summer when the weather is warm and somewhat dry. Some grasses and most Cyperus spp. (Flat Sedges) have a C4 metabolism. The chemical pathway of C4 metabolism is slightly different from that of C3 metabolism (see the description above).

Caducous: [Petals, Sepals, Stipules] {persistence} Falling off very early, as stipules that drop soon after the leaf develops.

Calyx: The collective term for all of the sepals of a flower; the outer perianth whorl.

CAM: Crassulacean Acid Metabolism

Canescent: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} Gray or white in color due to a covering of short, fine, gray or white hairs.

Capitulate: collected into small capitula

Capitulum: a simple racemose inflorescence in which the primary axis is shortened and dilated forming a rounded or flattened cluster of sessile flowers (as in the buttonbush and in all composite plants) -- called also head

Capsule: [Fruits] {type} A dry fruit that opens (dehisces) in any of various ways at maturity to release few to many seeds.

Carnivorous: [Plants] {carnivory} Capturing animals (usually insects), digesting their tissues and assimilating the digested substances as nourishment, especially nitrogen. [

Carpel: The basic ovule-bearing unit of flowers, thought to be evolutionarily derived from an infolded leaf-like structure; equivalent to a simple pistil or a division of a compound pistil.

Carpophore: a slender often forked prolongation of a receptacle or pistil or both which develops as the fruit ripens and from which the ripened carpels are suspended (as in members of the genus Geranium and in the Umbelliferae)

Caryopsis: [Fruits] {type} A more or less small, dry fruit that does not split open at maturity (indehiscent), with a thin wall surrounding and fused to the single seed, as the fruits of the grass family (Poaceae); a grain.

Catkin: [Inflorescences] {type} A pendent, more or less flexible, spike-like inflorescence with numerous small flowers, typically of only one sex (unisexual), lacking petals and subtended by scaly bracts, as in willows (Salix) and birches (Betula); catkins are often wind pollinated and fall as a unit after flowering or fruiting.

Caudate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape}

Caudex: This is a spheroid enlargement at the base of a plant that is usually below the surface of the soil (in herbaceous plants). A caudex is woody and functions as a storage organ for nutrients and water. One or more stems develop from the top of a caudex, while coarse roots radiate below. See line drawing of a Caudex.

Cauline: [Leaves] {position} With leaves positioned along the stem above ground level.

Central Axis: This expression usually refers to the central stalk of an inflorescence that is a spike, raceme, or panicle. Sometimes it refers to the central stalk (or rachis) of a compound leaf.

Cereal: a plant (as a grass) yielding farinaceous seeds suitable for food (as wheat, maize, rice)

Chambered: [Pith] {type} Interrupted by more or less regularly spaced cavities.

Checkered: [Bark of mature trunks] {surface appearance} Bark divided into small squarish plates, resembling alligator leather, as in flowering dogwood (Cornus florida).

Ciliate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form}; [Buds] {pubescence type} With a fringe of hairs along the margin.

Circular: [Leaf cross section] {shape} Round in cross section.

Circumferential: [Stipules, Stipule scars] {extent} Encircling the twig.

Circumscissile: dehiscing by a transverse fissure around the circumference

Circumscissile capsule: [Fruits] {type} A capsule that splits open (dehisces) by a horizontal line around the fruit, the top coming off as a lid.

Clasping: [Leaf bases, Leaflet bases] {shape} The base partly surrounding the stem.

Claw: the slender, prolonged basal portion of certain petals (as in the pink)

Clawed: having claws (see above)

Cleft: The leaf is sharply divided into lobes; it may be pinnately or palmately cleft. The ends of the lobes are often pointed, rather than rounded. See line drawing of Cleft shape.

Circinate: characterized by hor having the form of a flat coil of which the apex is the center -- used esp. of arrangements of plant parts in vernation and of developing fern fronds

Clouded: [Leaf lower surface, Leaf upper surface] Colors are unequally blended together.

Clustered: [Leaves] {insertion}; [Needles] {presence of clusters or fascicles} Leaves grouped closely together at the point of attachment and tending to diverge from one another, as the leaves on short shoots in Gingko (Gingko biloba) or the needles on short shoots in larches (Larix).

Collateral: [Buds] {position} In pairs, within or straddling the leaf axils; often located on either side of an axillary bud.

Column: the united monadelphous stamens in mallows b : the united androecium and gynoecium in orchids

Composite Flower: A flowerhead consisting of numerous small florets. This flowerhead may have ray florets (a small flower resembling a petal) and/or disk florets (a small tubular flower with tiny lobes). The florets are held together by floral bracts surrounding the base of the flower.

Compound: [Leaves] {complexity} Divided into two or more equivalent parts, as a leaf that consists of multiple, distinct leaflets; not simple.

Compound dichasium: [Inflorescences] {type} A determinate, cymose inflorescence with the main axis bearing a terminal flower and a pair of opposite or nearly opposite lateral branches, each branch also bearing a terminal flower and a pair of lateral flowers or branches; a branched dichasium.

Compound ovary: An ovary formed by the fusion of the bases of two or more carpels; recognizable by the presence of more than one area of placentation, locule, ovary lobe, style (or style branch), or stigma.

Compound umbel: [Inflorescences] {type} An inflorescence composed of several branches that radiate from almost the same point, like the ribs of an umbrella, each terminated by a secondary set of radiating branches that end in one or more flowers, the upper surface of the whole inflorescence rounded, or more or less flat; a branched umbel; as in Queen Annes lace (Daucus carota).

Cone: Reproductive structures in conifers comprised of scales and/or other types of modified leaves densely arranged on a central stalk; female, or seed cones, bear ovules on the surface of their scales; male cones produce pollen.

Conic: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Rounded in cross section, broadest at the base and essentially triangular in outline; cone-shaped.

Conifer: Cone-bearing plants, such as pines (Pinus).

Conspicuous lenticels: [Bark of mature trunks] {surface appearance} Bark with readily visible pores or lenticels.

Continuous: [Pith] {type} Uninterrupted by cavities and essentially homogenous in texture; solid.

Cordate: [Leaf bases, Leaflet bases, Leaflets, Leaves] Heart-shaped, with the notch at the base.

Corm: [Stems] {type} A short, solid, vertical, usually underground, enlarged stem with leaves that are dry and scale-like or absent.

Corolla: The collective term for all of the petals of a flower; the inner perianth whorl.

Corona: an appendage or series of united appendages borne on the inner side of the corolla in certain flowers (as in the daffodil, jonquil, and milkweed) and often resembling an additional whorl of the perianth

Corymb: [Inflorescences] {type} A racemose inflorescence with the individual flower stalks (pedicels) progressively shorter toward the apex so the flowers are all at about the same level, forming a flat or rounded surface across the top.

Cotyledon: the first leaf or one of the first pair or whorl of leaves developed by the embryo in seed plants and in ferns and related plants that functions primarily to make stored food in the endosperm available to the developing young plant but in some cases acts as a storage or photosynthetic organ

Creeping: tending to spread over the ground or other substrate

Crenate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} With rounded teeth along the margin; scalloped.

Crenulate: [Leaf margins, Leaflet margins] {form} With very small, rounded teeth along the margin; finely crenate or small-scalloped.

Crisped: [Leaf margins, Leaflet margins] {form} Margins divided and twisted in more than one plane, as parsley (Petroselinum crispum) leaves; curled.

Cross-shaped: two intersecting lines or bars usu. of equal or approximately equal length and crossing at or about their midpoints

Crumpled: wrinkled, creased, or bent out of shape by or as if by pressing, folding, or crushing

Culm: the jointed stem of a grass usu. hollow except at the often swollen nodes and usu. herbaceous except in the bamboos and other arborescent grasses; also one of the solid stems of sedges, rushes, and similar monocotyledonous plants

Cuneate: [Leaf bases, Leaflet bases] {shape} Wedge-shaped and tapering to a point at the base.

Cupule: A cup-like structure at the base of some fruits, such as the acorns of oaks (Quercus), composed of a persistent, usually dried, whorl of bracts (involucre) or other sterile floral parts, that are often partially fused.

Cyathium: [Inflorescences] {type} An inflorescence consisting of a single, naked, terminal pistillate flower with several tiny, naked, lateral staminate flowers, the whole more or less enclosed by a cuplike whorl of bracts (involucre) and resembling a single flower; as in poinsettias (Euphorbia).

Cylindric: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Rounded in cross section with a more or less uniform diameter and blunt ends; cylinder-shaped.

Cyme: [Inflorescences] {type} Generally, a determinate, compound, and frequently more or less flat-topped inflorescence; the basic cymose unit is a three-flowered cluster composed of a main stalk bearing a terminal flower and below it, two stalked, lateral flowers, each with a reduced leaf or bract at the base.

Cymose: In the form of a simple or compound cyme; bearing cymes.

Cypsela: [Fruits] {type} A dry, one-seeded fruit that does not split open at maturity (indehiscent), with persistent perianth tissue (pappus) attached at the top, as in some members of the Asteraceae.

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D

Deciduous: (1) [Leaves] {duration} Falling at the end of one growing season, as the leaves of non-evergreen trees; not evergreen. (Compare with evergreen and semi-evergreen.)

Deciduous: (2) [Seed cone armature] {persistence} Armature tending to fall off while the cone is otherwise still intact.

Decurrent: [Leaf bases, Leaflet bases]{shape}With the leaf base extending downward along the stem

Decussate: [Leaves] {insertion} Arranged along the stem in pairs, with each pair at right angles to the pair above or below; a form of opposite arrangement.

Deeply lobed: [Leaflets, Leaves, Petals, Sepals] {lobing} With lobes that are cut approximately = to > the distance to the midrib or base; deeply cleft.

Dehiscent: Splitting or forming one or more openings in a regular pattern at maturity enabling the contents to be released for dispersal, as certain fruits, such as capsules, that split open when ripe releasing seeds.

Deltoid: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Similar in shape to an equilateral triangle, with the point of attachment along one of the sides; like the Greek letter delta.

Dentate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} Toothed along the margin, with pointed teeth that are directed outward rather than forward.

Denticidal capsule: [Fruits] {type} A capsule that opens (dehisces) at the apex, leaving a ring of teeth.

Denticulate: [Leaf margins, Leaflet margins] {form} Toothed along the margin, with very small, pointed teeth that are directed outward rather than forward; finely dentate.

Determinate inflorescence: An inflorescence in which the terminal or central flower opens first, halting further elongation of the main axis, as in cymes.

Diadelphous: of stamens united by the filaments into two fascicles

Diaphragmed: [Pith] {type} Uninterrupted by cavities but with regularly spaced partitions of denser tissue.

Dichotomous: dividing into two parts or groups

Dimorphic: having two forms

Dioecious: [Plants] {distribution of gender} Having functionally unisexual (i.e. separate male and female) flowers or cones, which are borne on different plants within the species; thus some plants are male and others are female.

Disarticulation: As the spikelets of grasses become mature, their floral scales (whether glumes and/or lemmas) become separated from their stems and fall to the ground. When the glumes (the lowermost scales) persist on their stems while the lemmas fall to the ground, this is referred to as 'disarticulation above the glumes.' When both glumes and lemmas separate from their stems and fall to the ground, this is referred to as 'disarticulation below the glumes.'

Disciform: of round or oval shape

Discoid: relating to or having a disk as a of a composite floret : situated in the floral disk : being a disk floret b of a composite flower head > having only tubular florets

Discoidal [Leaf lower surface, Leaf upper surface] {color variegation} A single large spot of color in the center of another.

Disk: the central portion of the flower head of a typical composite composed of closely packed tubular flowers

Disk floret: one of the tubular flowers in the disk of a composite plant

Dissected: deeply divided into many narrow segments (h)

Dissepiment: a separating tissue PARTITION SEPTUM

Distichous: [Leaves] {habit} With leaves arranged along the stem in two rows, the rows

Distinct: separate, not attached to like parts (h)

Dotted [Leaf lower surface, Leaf upper surface] {color variegation} The color disposed in very small round spots.

Doubly serrate: [Leaf margins, Leaflet margins] {form} Margin with teeth of two sizes (small teeth on the big teeth), the teeth bent toward the apex; doubly sawtoothed.

Drupe: [Fruits] {type} A fleshy fruit that does not split open at maturity (indehiscent), with a soft outer wall and one or more hard inner stone(s) each usually containing a single seed, as cherries and plums (Prunus).

Drupelet: one of the individual parts of an aggregate fruit (as the raspberry)

Duration: The length of time that a plant or any of its component parts exists.
opposite one other; two-ranked

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E

Edged: [Leaf lower surface, Leaf upper surface] {color variegation} One color is surrounded by a very narrow rim of another.

Ellipsoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Widest near the middle, with convex sides tapering equally toward rounded ends, and rounded in cross section; elliptic or oval-shaped in outline.

Ellipsoid-cylindric: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between ellipsoid and cylindric.

Elliptic: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Widest near the middle, with convex sides tapering equally toward both ends

Emarginate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} With a notch at the apex.

Endemic: restricted to or native to a particular area or region : INDIGENOUS -- used of kinds of organisms

Ensiform: [Leaflets, Leaves] {shape} Long and moderately slender, flat in cross section, gradually tapering to a pointed apex; sword-shaped; as an Iris leaf.

Entire: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} With relatively smooth margins that lack teeth, spines or other projections (the margins may be lobed); with a continuous margin.

Epidermal: of, relating to, or arising from the epidermis [which is] a layer of primary tissue in higher plants that is commonly one cell thick, often cutinized on its outer surface, and continuous in young plants except over the stomata, that provides protecti on to underlying parts against mechanical injury and desiccation, and that is largely replaced (as by periderm or exodermis) in older plants except on leaves and herbaceous stems

Epidermis: The outermost layer of cells of leaves, young stems and roots.

Epigynous: [Flowers] {perianth position} With the free portion of the perianth (the whorl of sepals and petals) borne at the top of a floral cup which is fused to and wholly encloses the ovary, the perianth thus appearing to arise from the top of the ovary.

Epiphytic: [Plants] {habit} Physically supported in its entirety by another plant through all or the major part of its life, but not drawing direct nutrition from the host plant.

Episepalous: growing on or adnate to the sepals

Equitant: [Leaves] {habit} With leaves clustered at the base of the stem and in two ranks, the sides overlapping at the base and often sharply folded along their midridge, as in Iris.

Erose: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} With the margin irregularly toothed, as if gnawed.

Estipulate: without stipules

Even-pinnate: [Terminal leaflet] {presence} Pinnately compound with an even number of leaflets, none truly terminal.

Evergreen: [Leaves] {duration} Bearing green leaves through the winter and into the next growing season; persisting two or more growing seasons; not deciduous.

Exfoliating: [Bark of mature trunks] {surface appearance} Bark splitting or cracking and falling away in thin patches or sheets, as in shagbark hickory (Carya ovata).

Exudate: exuded matter fr. exude : to ooze out slowly in small drops through openings (as pores) . . . b : to flow slowly out : issue slowly forth

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F

Falcate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Long, arcing to one side and

Fan-shaped: [Leaflets, Leaves] {shape} Shaped like a fan, as a Gingko leaf.

Fascicle: [Inflorescences] {type} A tight cluster of stalked (pedicellate) flowers, the stalks originating very close to one another and diverging little if at all.

Fascicled: [Leaves] {insertion}; [Needles] {presence of clusters or fascicles} In a tight bundle, several leaves appearing to arise from a common point and diverging little if at all, as the needles of many pines (Pinus).

Fibrous: [Roots] {type} With several to many relatively slender roots of about the same diameter.

Filament: The stalk of a stamen, which supports an anther at its tip.

Filiform: [Leaflets, Leaves] {shape} Long and very slender, basically round in cross section and of uniform diameter; thread-like.

Flagellum: (pl. flagella) a long tapering process that projects singly or in groups from a cell or microorganism, is possibly equivalent to a much enlarged cilium, and is the primary organ of motion of flagellated protozoans and many algae, bacteria, and zoospores <.b>4 : a long slender shoot (as a stolon or runner) of a plant

Flaky: [Bark of mature trunks] {surface appearance} Bark with more or less regular, thin flakes, as in eastern hophornbeam (Ostrya vriginiana) and many pines (Pinus).

Fleshy: [Seed cone scales] {type} Fairly firm and dense, juicy or at least moist, and easily cut.

Floral: upon, within, or associated with the flowers.

Floral Bracts: A compound flower often has floral bracts that circumscribe its base, particularly among members of the Asteraceae (Aster family). These scale-like bracts surround the ovaries of the flower and they are often appressed together. They are often referred to as 'involucral bracts' or 'phyllaries' by botanical authorities.

Floral cup: A cup or tube usually formed by the fusion of the basal parts of the sepals, petals and/or stamens, and on which they are seemingly borne; surrounds the ovary, or ovaries, and may be fused wholly, partly or not at all to them; the shape varies from disc-like to cupshaped,flask-like or tubular; a hypanthium.

Floret: A very small, structurally specialized flower, especially those of the grasses (Poaceae) and the sunflower family (Asteraceae).

Flower: The reproductive structure in flowering plants (angiosperms), consisting of stamens and/or pistils, and usually including a perianth of sepals and/or petals.

Follicle: [Fruits] {type} A usually dry fruit, with one interior chamber or locule, and splitting open (dehiscing) lengthwise along a single line, as in milkweed (Asclepias). [

Forbs: These are plants that produce flowers with conspicuous petals and/or sepals; the flowers of such plants are often showy and insect-pollinated. In contrast, grasses (Poaceae), sedges (Cyperaceae), and miscellaneous other plants are not forbs because their wind-pollinated flowers lack petals and sepals, or their petals and sepals are tiny and inconspicuous. Such wind-pollinated flowers are not very showy, although there are some exceptions.

Four-angled: [Leaf cross section] {shape} More or less diamond-shaped in cross section.

Four-ranked: [Leaves] {habit} With leaves arranged in along the stem in four rows.

Free-central: [Placentation] {type} Attachment of ovules to a free-standing central axis in a compound ovary which has a single inner compartment (unilocular), and thus no interior partitions (septa).

Fruit: The seed-bearing structure in flowering plants, consisting of one or more matured or ripened pistil(s), along with any persisting accessory parts such as sepals or receptacle.

Funnelform: A corolla that is shaped like a funnel, being narrow and tubular at the base, but flaring outward toward the outer margin. The corollas of Ipomoea spp. (Morning Glories) and Calystegia spp. (Bindweeds) are funnelform.

Furrowed: [Bark of mature trunks] {surface appearance} Bark with relatively long narrow depressions or grooves, as in tulip-tree (Liriodendron tulipifera).

Fusiform: [Buds] {shape} Elongate, broadest at the middle, evenly tapering to either end, and rounded in cross section; spindle-shaped.

Fusion: The physical connection of equivalent or dissimilar structures, as fused sepals or petals.

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G

Gametophyte: the individual or generation of a plant exhibiting alternation of generations that bears sex organs, constitutes the major part of the plant body in most algae, fungi, and mosses, exists as an independent transitory thalloid body in ferns and related plants, and is reduced to a microscopic or rudimentary structure in see plants -- distinguished from sporohphyte

Geminate: In pairs, as a leaf which is divided into two leaflets.

Germination: The beginning or resumption of growth by a seed, bud or other structure.

Glabrate: [2-4-year-old twigs, Buds, Leaf lower surface, Leaf upper surface, Petals, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence} Becoming glabrous; almost glabrous; pubescent when young, but losing the hairs in maturity.

Glabrous: [2-4-year-old twigs, Buds, Leaf lower surface, Leaf upper surface, Petals, Petioles,Phyllaries, Rachises, Sepals, Young twigs] {pubescence} Lacking plant hairs (trichomes).

Glandular: (1) [Petioles, Rachises] {special surface features} Bearing secreting organs, or glands.

Glandular: (2) [Stipules] {type} In the form of a secreting organ or gland. blade-like, scale-like and spinose.)

Glaucous: [Buds, Young twigs, Leaves] Covered with a whitish or bluish waxy coating (bloom) that can sometimes be rubbed off.

Globose: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Circular in cross section and in outline when viewed from any angle; like a globe or sphere.

Glochid: glochidium : a barbed hair or spine (as on the massulae of a water fern or on some cacti)

Glomerule: [Inflorescences] {type} A dense cluster of flowers.

Glossy: Lustrous or shiny, as the upper surface of southern magnolia (Magnolia grandiflora) leaves.

Glume: one of the two empty bracts at the base of the spikelet in grasses

Glutinous: Gluey, sticky or gummy; covered with sticky exudates.

Grain: A grain is a seed with a hard coat. It typically refers to the seeds of grasses (Poaceae). Sometimes this term refers to a particle of pollen (e.g., a grain of pollen).

Grass: Members of the Poaceae (Grass family) are true grasses.

Grass-like herbaceous: [Plants] {habit} Herbaceous with relatively long, narrow leaves appearing similar to those of grasses (Poaceae).

Grooved: [Apophyses] {texture} With a narrow depression or groove.

Gymnosperm: [Plants] {major group} A seed plant which produces seeds that are not enclosed inside an ovary, as the conifers.

Gynecandrous: This refers to a spikelet that has pistillate (female) flowers above the staminate (male) flowers. Some sedges (e.g., Carex spp.) have this arrangement of flowers on the same spikelet.

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H

Habit: The general appearance, characteristic form, or mode of growth of a plant.

Half-inferior: [Ovaries] {position} With the lower portion of the ovary enclosed by and fused to a floral cup, the whorl of sepals and petals (perianth) and/or stamens (androecium) thus appearing to arise from near the middle of the ovary.

Halophyte: a plant that grows naturally in soils having a high content of various salts, that usu. resembles a true xerophyte and that occurs in many families (as Chenopodiaceae, Compositae, Plumbaginaceae)

Hastate: [Leaf bases, Leaflet bases, Leaflets, Leaves] {shape} Arrowhead-shaped, but with the basal lobes turned outward rather than downward.

Head: [Inflorescences] {type} An inflorescence with crowded, sessile or nearly sessile, small flowers (florets) borne on a common receptacle which is convex or flat and often disc-shaped; characteristic of the family Asteraceae.

Helicoid cyme: [Inflorescences] {type} A cyme in which the lateral branches develop on only one side, all segments branching on the same side, causing the inflorescence to curve or coil.

Helophyte: a perennial marsh plant having its overwintering buds under water

Hemi-parasitic: [Plants] {nutrition} Partially parasitic; in plants, photosynthetic but deriving at least some nutrients from a host organism.

Herbaceous: [Plants] {woodiness} Having little or no living portion of the shoot persisting aboveground from one growing season to the next, the aboveground portion being composed of relatively soft, non-woody tissue.

Hesperidium: [Fruits] {type} A specialized berry with a leathery skin or rind, and a fleshy interior divided into sections or locules, as lemons and oranges (Citrus).

Heterosporous: characterized by the production of asexual spores of more than one kind

Hip: [Fruits] {type} An aggregation of achenes surrounded by an urn-shaped, more or less fleshy floral cup or hypanthium, as in roses (Rosa).

Hirsute: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With coarse, stiff hairs.

Hispid: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} With stiff, bristly, usually stout-based hairs.

Hollow: [Pith] {type} With an uninterrupted central cavity, the pith lacking or disintegrating prior to maturity.

Homosporous: characterized by the production by various plants (as the club mosses and horsetails) of asexual spores of only one kind

Hoods: Erect columnar structures on the upper part of a Milkweed flower in the Asclepiadaceae.

Horn: A slender horn-like structure inside or adjacent to the hood of a Milkweed flower in the Asclepiadaceae. The horns are straight or curved, and usually shorter than the hoods. The flowers of some Milkweed species lack horns.

Host: a living animal or plant affording subsistence or lodgment to a parasite

Husk: the outer covering of a kernel or seed esp. when dry and membranous

Hydrophyte: a vascular plant growing wholly or partly in water; esp : a perennial aquatic plant having its overwintering buds under water b : a plant requiring an abundance of water for growth and growing in water or in soil too waterlogged for most other plants to survive -- compare mesophyte, xerophyte

Hygroscopic: sensitive to moisture b : induced by moisture

Hypanthium: an enlargement of the usu. cup-shaped receptacle bearing on its rim the stamens, perals, and sepals of a flower and often enlarging and surrounding the fruits (as in the rose hip)

Hypanthium: A cup or tube usually formed by the fusion of the basal parts of the sepals, petals and/or stamens, and on which they are seemingly borne; surrounds the ovary, or ovaries, and may be fused wholly, partly or not at all to them; the shape varies from disc-like to cup shaped, flask-like or tubular; a floral cup.

Hypogynous: [Flowers] {perianth position} With the perianth (the whorl of sepals and petals) not fused into a floral cup of any kind and arising at the same level as the base of the ovary.

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I

Imbricate: (1) [Leaves] {habit} Overlapping, as the shingles on a roof.

Imbricate: (2) [Bud scales] {type} Overlapping, as the shingles on a roof.

Impressed: [Leaf upper surface venation] {relief}

Incised: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} Margins sharply and deeply cut, usually jaggedly.

Inconspicuous: [Stipule scars] {presence} Not readily visible.

Indehiscent: Not splitting or forming an opening at maturity, the contents being released for dispersal only after decay, digestion or erosion of the structure, as certain fruits, such as achenes and berries, that retain their seeds when ripe. (

Indeterminate inflorescence: An inflorescence in which the lowermost or outermost flower opens first, with the main axis often elongating as the flowers develop, as in racemes.

Indusium: The sorus (or spore-bearing structure) of some ferns is partially covered by a pale membrane that is called an 'indusium.' The indusium may fade away as the fertile leaf of a fern matures. The plural form of this term is 'indusia.'

Inferior: [Ovaries] {position} With the ovary wholly enclosed by and fused to a floral cup, the whorl of sepals and petals (perianth) and/or stamens (androecium) thus appearing to arise from the top of the ovary.

Inflorescence: 1) The mode or pattern of flower bearing; the arrangement of flowers on the floral axis. 2) A basic unit of the flower-producing portion of a plant, composed of one or more flowers and any supporting stalks and appendages (e.g. bracts, involucres, etc.); a flower cluster.

Infrapetiolar: [Buds] {position} Axillary and surrounded by the base of the leaf stalk or petiole.

Insertion: The location of points of attachment of a structure (e.g., a leaf) to some dissimilar bearing structure.

Internode: The portion of a stem between two nodes, i.e. the part where leaves and/or branches do not arise.

Involucre: A whorl of bracts subtending a flower or flower cluster.

Involute: [Leaf margins, Leaflet margins] {vertical disposition} With margins rolled inward, toward the upper side. (Compare with plane and revolute.)

Irregular: of a flower or its parts : lacking uniformity; specif : zygomorphic (or) bilaterally symmetrical; said of a flower in which all parts are not similar in size and arrangement on the receptacle (compare regular, and see zygomorphic) (h)

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K

Keel: A longitudinal ridge, more or less triangular in cross section, like the keel of a boat.

Keeled: (2) [Apophyses] {keels} With a vertical ridge or keel.

Keeled above: [Leaves] {keels} With a longitudinal ridge or keel, more or less triangular in cross section, running down the center of the upper surface of the leaf.

Keeled below: [Leaves] {keels} With a longitudinal ridge or keel, more or less triangular in cross section, running down the center of the lower surface of the leaf.

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L

Lacerate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} Margins irregularly cut, appearing torn.

Laciniate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} Cut into narrow, ribbon-like segments.

Lance-cylindric: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between lanceoloid and cylindric.

Lance-obovoid: [Seed cones] {shape before opening, shape when open} Intermediate in shape between lanceoloid and obovoid.

Lanceolate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Several times longer than broad, widest near the base and tapering to a point at the apex; lance-head-shaped.

Lanceoloid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Considerably longer than broad, rounded or somewhat flattened in cross section, broadest near the base and somewhat concavely tapering toward the tip; lance-head shaped in outline.

Lance-ovoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between lanceoloid and ovoid.

Latex: a milky usu. white fluid of variable compostition that is usu. made up of various gum resins, fats, or waxes and often a complex mixture of other substances frequently including poisonous compounds, this is found in or produced by cells of plants especially of the Asclepiadaceae but also of the Apocynaceae, Sapotaceae, Euphorbiaceae, Moraceae, Papaveraceaea, , and Compositae.

Leaf: A lateral outgrowth of a stem, usually green and photosynthetic, and often consisting of a stalk (petiole) and an expanded portion (blade); leaves may also be needle-like or scale-like in form.

Leaf complexity: The division (or not) of a leaf into distinctly separate segments or leaflets; whether a leaf is simple or compound.

Leaf insertion: The position of leaves as defined by the relative location of their points of attachment on the stem (e.g. alternate, opposite, whorled, etc.).

Leaf scar: The scar remaining on a twig at the former place of attachment of a leaf, after the leaf has fallen.

Leaf venation: The visible pattern of veins on a leaf.

Leaflet: One of the separate, leaf-like segments of a compound leaf.

Leathery: [Seed cone scales] {type} Moderately thick, tough and pliable.

Legume: [Fruits] {type} A usually dry fruit that splits open (dehisces) lengthwise along two sutures and has a single interior chamber (locule), as in the pea family (Fabaceae).

Lemma: A lemma is one of the floral scales in a spikelet of grass; the lemmas are located above the glumes. Lemmas usually occur in pairs in each spikelet, although sometimes they occur individually. Typically, one lemma in a pair is fertile and contains a floret, while the other lemma is sterile. The lemmas provide some protection for the reproductive organs of the florets and its developing seed (or grain). Like the glumes, the lemmas are often keeled and somewhat flattened. The fertile and infertile lemmas can appear nearly identical to each other, or their appearance may be somewhat different from each other. Sometimes the tips of the lemmas are awned.

Lenticel: The specialized openings in the bark of some woody stems that provide a passage for gas exchange, often appearing as small, circular to elongate marks on the surface of the bark.

Lepidote: Covered with small scales.

Ligule: A structure on the inner side of a leaf at the junction of the sheath and blade. This structure consists of thickened tissue that may contain papery membranes or a row of hairs. The characteristics of a ligule are more observable when the blade of a leaf is pulled away from the culm. Sometimes the ligule is used in the identification of grasses and sedges.

Linear: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Long and narrow, with the sides more or less straight and parallel. (Compare with acicular, ensiform, filiform and lorate.)

Lobe: A more or less major protrusion or segment of a leaf or leaflet delimited by concavities (sinuses) in the leaf margin.

Locule: A distinct compartment or cavity within organs such as ovaries, anthers or fruits.

Loculicidal capsule: [Fruits] {type} A capsule that splits open (dehisces) lengthwise directly into the locules or chambers of the ovary, more or less midway between the ovary partitions.

Loment: [Fruits] {type} A usually dry fruit that breaks apart crosswise at points of constriction into one-seeded segments, as in beggars ticks (Desmodium); considered to be a modified legume.

Lorate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Long and moderately narrow, flat in cross section, with sides more or less straight and parallel, often flexible and curving; strapshaped.

Lyrate: [Leaflets, Leaves] {shape} Pinnately lobed, with a large, rounded terminal lobe and smaller lower lobes; lyre-shaped.

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M

Marbled [Leaf lower surface, Leaf upper surface] {color variegation} A surface traversed by irregular veins of color, as a block of marble.

Margin: The edge, as in the edge of a leaf blade.

Marginal: [Placentation] {type} Attachment of ovules along one side of a simple ovary.

Mericarp: [Fruits] {type} One of the segments of a schizocarp once it has split apart, often appearing to be a separate fruit; usually one-seeded and not splitting open at maturity (indehiscent); as the small, relatively hard-coated nutlets in the mint familiy (Lamiaceae) or the individual winged samaras of maples (Acer).

Mesic : of a habitat : having or characterized by a moderate amount of moisture : neither hydric not xeric; of a plant or flora : mesophytic

Midrib: A main or primary vein running lengthwise down the center of a leaf or leaf-like structure; a continuation of the leaf stalk (petiole); the midvein.

Midvein: A main or primary vein running lengthwise down the center of a leaf or leaf-like structure; a continuation of the leaf stalk (petiole); the midrib.

Moderately lobed: [Leaflets, Leaves, Petals, Sepals] {lobing} With lobes that are cut approximately < to = the distance to the midrib or base.

Monadelphous: united by the filaments into one group usu. forming a tube around the gynoecium

Monocarpic: bearing fruit but once and dying--used esp. of annual and biennial flowering plants; compare century plant

Monocarpous: having a single ovary

Monoclinous: having the stamens and pistils in the same flower

Monoecious: Plant species that produce both male and female flowers, but not perfect flowers, on the same plant. An example of a monoecious species is Xanthium strumarium (Common Cocklebur).
Monophyletic: developed from a single common parent form

Monopodial: having or involving offshoots from a main axis

Motile: exhibing or capable of movement

Mucronate: [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Ending abruptly in a short, hard point. (Compare with apiculate, aristate and caudate.)

Multilocular: With more than one interior compartment or locule.

Multiple fruit: [Fruits] {type} A fruit formed from several flowers (and associated parts) more or less coalesced into a single structure with a common axis, as a mulberry (Morus) or pineapple (Ananas comosus).

Mycorrhiza: the symbiotic association of the mycelium of a fungus (as various basidiomycetes and ascomycetes) with the roots of a seed plant (as various conifers, beeches, heaths, and orchids) in which the hyphae form an interwoven mass investing the root tips or penetrate the parenchyma of the root

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N

Naked: [Bud scales] {type} With no scales covering the immature shoot.

Nearly sessile: [Flowers, Leaflets, Leaves, Seed cones] {form of attachment} With a very short, somewhat indistinct stalk. (Compare with petiolate, petioulate, sessile and stalked.)

Nearly symmetric: [Seed cones] {symmetry} Not fully symmetric, but divisible into nearly equal halves along one or more planes.

Nectar: A sugary, sticky fluid secreted by many plants.

Nectary-bearing: [Petioles, Rachises] {special surface features} Bearing a glandular structure that secretes nectar [modified from W&K, p. 598 (see nectary)], often appearing as a protuberance, scale or pit.

Needle-like: [Leaves] {general form} With leaves that are more or less needle-shaped, and usually evergreen; they may be flattened as in hemlocks (Tsuga) or more rounded as in pines (Pinus).

Neuter: having no generative organs

Node: The portion of a stem where leaves and/or branches arise; often recognizable by the presence of one or more buds.

Not persistent: [Seed cones] {persistence} Falling from the branch soon after shedding seeds.

Not serotinous: [Seed cones] {serotiny} Having cones that open when the seeds ripen or soon thereafter.

Nucleus: an element of the protoplasm of most plant and animal cells that is regarded as an essential agent in their metabolism, growth, and reproduction and in the transmission of hereditary characters and that typically consists of a more or less rounded ma ss of nucleoplasm made up of a hyaline ground substance in which is suspended a network rich in nucleoproteins from which the mitotic chromosomes and one or more nucleoli condense, the whole being enclosed by a nuclear membrane

Nut: [Fruits] {type} A more or less large, dry fruit that does not split open at maturity (indehiscent), with a single inner chamber and a thick, bony wall surrounding a single seed, as walnuts (Juglans).

Nutlet: a small nut-like fruit (as of many plants of the family Boraginaceae)

Nutrition: Mode of acquiring substances necessary for growth and development.

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O

Obcordate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Heart-shaped with the point of attachment at the narrow end; inversely cordate.

Obdeltoid: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Similar in shape to an equilateral triangle, with the point of attachment at the narrow end; inversely deltoid.

Oblanceolate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Several times longer than broad, widest near the apex and tapering to a point at the place of attachment; inversely lanceolate.

Oblique: [Leaf bases, Leaflet bases] {shape} Having an asymmetrical base.

Oblong: (1) [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Shaped like a compressed oval, with the sides approximately parallel for most of their length. (Compare with elliptic.)

Oblong: (2) [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Shaped like an elongated ellipsoid, the sides almost parallel from near one end to near the other end.

Oblong-cylindric: [Seed cones] {shape before opening, shape when open} Intermediate in shape between oblong and cylindric.

Oblong-ovoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between oblong and ovoid.

Obovate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Egg-shaped with the point of attachment at the narrower end; inversely ovate.

Obovoid: [Seed cones] {shape before opening, shape when open} Egg-shaped with the base at the narrow end; inversely ovoid.

Obtuse: (1) [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} More or less blunt at the apex, with the sides coming together at an angle of greater than 90:.

Obtuse: (2) [Leaf bases, Leaflet bases] {shape} More or less blunt at the base, with the sides coming together at an angle of greater than 90:.

Ocellated [Leaf lower surface, Leaf upper surface] {color variegation} A broad spot of some color has another spot of a different color within it.

Ocrea: a tubular sheath around the base of the petiole consisting of a single stipule in the red clover or a pair of coherent stipules in the buckwheat family (Polygoniaceae)

Odd-pinnate: [Terminal leaflet] {presence} Pinnately compound with an odd number of leaflets, one of them terminal.

Once palmately compound: [Leaves] {complexity form} Compound with leaflets all attached at a common point and diverging from one another.

Once pinnately compound: [Leaves] {complexity form} Compound with leaflets attached at different points along and on either side of a central axis or rachis.

Once pinnately lobed: [Leaves] {lobing form} With several main segments or lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Once pinnate-pinnatifid: [Leaves] {complexity form} Once pinnately compound with pinnatifid leaflets.

Opposite: [Leaves] {insertion} Positioned in pairs along the stem, the members of each pair at the same level across from one another; two leaves occurring at each node.

Orbiculate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Approximately circular in outline.

Oval: (1) [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Broadly elliptic, the width more than one-half the length, with rounded ends.

Oval: (2) [Leaf cross section] {shape} Elliptic in cross section.

Ovary: [Flowers] The lower portion of a pistil where ovules are borne; often distinguishable from the rest of the pistil by its larger circumference.

Ovate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Egg-shaped in outline, with the broader end near the base.

Ovoid: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Rounded in cross section, broadest near a bluntly rounded base and convexly tapering to a narrower rounded tip; egg-shaped.

Ovoid-acuminate: [Buds] {shape} Egg-shaped but with the narrow end concavely tapering to a point.

Ovoid-conic: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between ovoid and conic.

Ovoid-cylindric: [Buds] {shape}; [Seed cones] {shape before opening, shape when open} Intermediate in shape between ovoid and cylindric.

Ovoid-ellipsoid: [Buds] {shape} Intermediate in shape between ovoid and ellipsoid.

Ovule: The structure in flowering plants and gymnosperms which when fertilized develops into a seed.

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P

Painted: [Leaf lower surface, Leaf upper surface] {color variegation} Colors disposed in streaks of unequal intensity.

Palea: This is a thin inner scale that encloses the developing seed in a spikelet of grass. The palea resembles a fertile lemma (the outer scale), but it is usually smaller and more difficult to observe. Not all species of grass have a palea as a structure in their flowers.

Palmate: (1) With three or more leaflets, lobes or other structures arising from a common point and diverging from one another; arranged or structured in a hand-like pattern.

Palmate: (2) [Leaf venation, Leaflet venation] {form} With three or more primary veins arising from a common point at or near the base of the leaf or leaflet blade.

Palmately lobed: [Leaflet, Leaves] {lobing form} With three or more main segments or lobes essentially arising from a common point near the base of the leaf or leaflet blade; lobed in a hand-like pattern.

Pandurate: [Leaflets, Leaves] {shape} Basically inversely egg-shaped (obovate), but with two opposite rounded sinuses in the lower half and two small basal lobes; fiddle-shaped.

Panicle: [Inflorescences] {type} A branched raceme, the main axis either determinate or indeterminate, and the lateral branches racemose; more loosely, a much-branched inflorescence of various types.

Pappus: A ring or pair of hairs, bristles, awns or scales attached at the top of the ovary just beneath the petals, persisting in fruit and often aiding in dispersal by wind or animals, especially in the Asteraceae.

Parallel: [Leaf venation, Leaflet venation] {form} With two or more primary veins that run more or less parallel from the base to the tip of the leaf or leaflet blade.

Parasitic: [Plants] {nutrition} Living in or on an organism of a different species and deriving nutrients from it.

Parietal: [Placentation] {type} Attachment of ovules on the inner wall, or intrusions of the wall, of a compound ovary with a single inner compartment (unilocular).

Pectinate: [Leaves] {habit} Arranged like the teeth of a comb, the leaves slender and more or less perpendicular to the stem; comb-like.

Pedicel: The stalk of a individual flower, either that of a solitary flower or of single flowers in a multi-flower inflorescence.

Peduncle: The main stalk of a multi-flower inflorescence or of a cluster of flowers within an inflorescence.

Peltate: [Leaf bases, Leaflet bases] {shape} Having the leaf stalk (petiole) attached to the lower surface of the leaf, usually near the center.

Pepo: [Fruits] {type} A specialized berry with a hard or leathery rind and a fleshy interior surrounding a mass of seeds, without interior sections or locules, as melons and cucumbers (Cucumis).

Perennial: continuing or lasting for several years--used specif. of a plant (as delphinium) that dies back seasonally and produces new growth from a perennating part

Perfoliate: [Leaf bases, Leaflet bases] {shape} Having the base completely surrounding the stem, so that the stem appears to pass through the leaf.

Perfoliate: Where the bases of two opposite leaves wrap completely around the stem. It is also possible for the base of an alternate leaf to wrap completely around a stem, but this is less common.

Perianth: The collective term for the outer sterile parts of a flower, comprising the calyx (sepals) and the corolla (petals) when both whorls are present.

Perigynium: the saclike bract that subtends the pistillate flower of sedges of the genus Carex and that in fruit becomes a flask-shaped envelope investing the achene

Perigynous: [Flowers] {perianth position} With the free portion of the perianth (the whorl of sepals and petals) borne at the top of a floral cup which is either a) fused to and partially encloses the ovary (the perianth thus appearing to arise at a level between the bottom and top of the ovary), or b) free from the ovary and extending up and around it to some extent.

Persistent: (1) [Petals, Sepals, Stipules] {persistence} Remaining attached; not falling off early, as stipules that remain attached while the leaves are attached.

Persistent: (2) [Seed cones] {persistence} Remaining on the branch long after shedding seeds, sometimes for many years.

Persistent (3) : [Seed cone armature] {persistence} Remaining attached; not falling off while the cone is still intact.

Petal: A unit or segment of the inner floral envelope or corolla of a flower; often colored and more or less showy.

Petaloid: resembling a flower petal in form, appearance, or texture

Petiolate: [Leaves] {form of attachment} With a leaf stalk or petiole.

Petiole: a slender stem that supports the blade of a foliage leaf and that is usu. cylindrical but sometimes flattened or even winged

Petiolulate: [Leaflets] {form of attachment} With a leaflet stalk or petiolule.

Petiolule: The stalk of a leaflet of a compound leaf.

Photosynthetic: Able to convert light energy to chemical energy by means of chlorophylls and other photosynthetic pigments.

Phyllary: one of the involucral bracts subtending the flower head of a composite plant

Phyllode: a flat expanded petiole that replaces the blade of a foliage leaf, fulfills the same functions, and is analogous to but not homologous with a cladophyll

Phytomelanin: a papery "sooty" black layer over the seed of plants in the Asparagales, which includes agaves, aloes, onions and hyacinths. It is an important character for defining the group.

Pilose: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With soft, more or less straight hairs.

Pinked: with a saw-toothed edge

Pinna: a leaflet or primary division of a pinnate leaf or frond

Pinnate: (1) With several leaflets, lobes or other structures positioned along and on either side of a central axis; arranged or structured in a feather-like pattern.

Pinnate: (2) [Leaf venation, Leaflet venation] {form} With secondary veins arising from a single, large midvein.

Pinnately lobed: [Leaflets] {lobing form} With several main segments or lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Pinnatifid: With several lobes positioned along and on either side of a central axis; lobed in a feather-like pattern.

Pistil: The female or ovule-bearing organ of a flower, typically composed of an ovary, style and stigma.

Pistillate: [Flowers] {gender} Having functional pistils, but no functional stamens, making the flower unisexual and female.

Pith: The more or less soft and spongy tissue in the center of some stems and roots; sometimes degenerating to leave a hollow tube.

Placentation: The arrangement of ovules within the ovary.

Plane: [Leaf margins, Leaflet margins] {vertical disposition} With midrib and margin all in one plane, or nearly so; flat.

Plated: [Bark of mature trunks] {surface appearance} Bark with relatively large, more or less flat plates, as in mature loblolly pine (Pinus taeda) or mature white oak (Quercus alba).

Plumose: feathery, plume like. For example, wind-pollinated female flowers often have plumose stigmata so that they are more likely to receive the pollen of male flowers. Sometimes the hairs at the apex of a wind-dispersed achene (or seed) are called 'plumose' because they are branched and feathery in appearance, rather than straight and bristly

Pollen: The small, often powdery, grains which contain the male reproductive cells of flowering plants and gymnosperms.

Pollen cone: A male or pollen-producing cone; typically smaller and of shorter duration than seed cones.

Pollinium: (pl. Pollinia) the coherent mass of pollen grains that characterizes members of the Orchidaceae and Asclepiadaceae and often has a stalk bearing an adhesive disk that clings to visiting insects and facilitates withdrawal of the whole pollinium from its receptacle

Polygamous: [Plants] {distribution of gender} Having both bisexual (combined male and female) and unisexual (separate male and female) flowers or cones, which are borne on the same plant or on different plants of the same species.

Polyphyletic: derived (as by convergence) from more than one ancestral line

Pome: [Fruits] {type} A fleshy fruit that does not split open at maturity (indehiscent), with a more or less soft outer part derived from ripened hypanthium; the interior portion enclosing the seeds is divided into several sections or locules bounded by cartilaginous tissue; as apples (Malus).

Pore: a minute opening esp. in an animal or plant by which matter passes through a membrane

Poricidal capsule: [Fruits] {type} A capsule that develops openings or pores (dehisces), usually at or near the apex, through which the seeds pass to the outside; as in poppy.

Prickle: A small, sharp, non-woody structure developed from outgrowth of the surface of bark or epidermis.

Primary vein: A main vein in a leaf or other laminar structure from which other veins branch; the midvein or midrib when present.

Procumbent: being or having stems that trail along the ground without putting forth roots

Prophyll: a plant structure resembling a leaf (as a bracteole) or consisting of a modified or rudimentary leaf (as a foliar primordium)

Prostrate: trailing on the ground : PROCUMBENT

Pseudoterminal: [Buds] {position} Appearing to be the terminal bud, but actually the uppermost axillary bud with a subtending leaf scar on one side and the scar of the terminal bud often visible on the other side.

Puberulent: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With very short hairs.

Pubescence: The broad term for any type of plant hairiness.

Pubescent: [2-4-year-old twigs, Buds, Leaf lower surface, Leaf upper surface, Petals, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence} Bearing plant hairs (trichomes).

Pulp: the soft succulent part of fruit

Pulvinus: a cushionlike enlargement of the base of a petiole or petiolule consiting of a mass of large thin-walled cells surrounding a vascular strand and functioning in turgor movements of leaves or leaflets by reversible volume changes in the cells

Punctate glandular [Petioles, Rachises] {special surface features} Bearing sessile or embedded glands.

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R

Raceme: [Inflorescences] {type} An elongate, indeterminate inflorescence with stalked flowers borne singly along an unbranched main axis or rachis.

Racemose: In the form of a simple or compound raceme; bearing racemes.

Rachilla: This is a side stalk that diverges from the central stalk (rachis) in either a compound leaf (as in ferns) or an inflorescence (as in grasses and sedges)

Rachis: 1) The main axis of a compound leaf above the point of attachment of the lowermost leaflet; a continuation of the leaf stalk or petiole. 2) The main axis of a compound inflorescence above the point of attachment of the lowermost flower; a continuation of the inflorescence stalk or peduncle.

Radially symmetric: [Calyx, Corolla] {symmetry} Divisible into two essentially equal portions along more than one plane.

Raised: [Leaf upper surface venation] {relief}

Receptacle: 1) The more or less enlarged end of an individual flower stalk (pedicel) which bears some or all of the flower parts. 2) The enlarged end of a compound flower stalk (peduncle) bearing two or more flowers, or the florets of a head, as in the family Asteraceae.

Reflexed: [Leaves, Petals, Sepals] {vertical orientation} Bent backward or downward.

Reniform: [Leaflets, Leaves] {shape} Broader than long, broadly rounded and notched at the base; kidney-shaped.

Resupinate: inverted in position : appearing by a twist of the axis to be upside down or reversed

Reticulate: [Leaf venation, Leaflet venation] {form} With a clearly visible network of interconnecting veins.

Revolute: [Leaf margins, Leaflet margins] {vertical disposition} With margins rolled backward, toward the underside.

Rhizome: [Stems] {type} An underground, usually horizontal stem, often resembling a root but bearing nodes (points where leaves and/or branches can arise); usually with adventitious roots.

Rhombic: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Broadest at the middle, with more or less straight sides of equal length tapering to either end; diamond-shape.

Ridged: [Bark of mature trunks] {surface appearance} Bark with long, narrow protrusions or ridges, as in tulip-tree (Liriodendron tulipifera).

Root: The portions of a plant that are anatomically distinct from the shoot and that lack nodes and internodes; roots serve for anchorage, absorption and/or storage, and usually grow below ground.

Rosetted: [Leaves] {habit} With leaves in a tight cluster radiating from a central axis, usually at or near the base of the stem, as in dandelion (Taraxacum).

Rounded: [Leaf apices, Leaf bases, Leaflet apices, Leaflet bases, Petal apices, Phyllary apices, Sepal apices] {shape} Forming a smooth, continuous curve.

Rugose: Wrinkled.

Runcinate: [Leaflets, Leaves] {shape} Broad near the apex and tapering toward the base, with a series of coarse, sharp lobes on either side that mostly point toward the base, as a dandelion (Taraxacum) leaf.

Rust: or rust disease : any of numerous destructive diseases of plants produced by fungi of the order Uredinales and characterized by reddish brown pustular lesions on stems, leaves, or other plant parts

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S

Saccate: having the form of a sac or pouch

Sagittate: [Leaf bases, Leaflet bases, Leaflets, Leaves] {shape} Arrowhead-shaped, with the basal lobes directed downward.

Samara: [Fruits] {type} A winged, more or less dry fruit that does not split open at maturity (indehiscent), and contains a single seed, as in ash (Fraxinus) and maple (Acer).

Sap: The fluids circulated throughout a plant.

Saprophytic: [Plants] {nutrition} Obtaining nourishment from dead organic matter.

Scabrous: Rough and sand-papery to the touch, due to structure of the epidermis or to the presence of short stiff hairs.

Scale: 1) Small, flattened structures that are usually thin, dry and membranous in texture. 2) Small, often triangular shaped, leaves that are appressed to the branchlets as in Juniper (Juniperus).

Scale-like: (1) [Leaves] {general form} With small, typically triangular-shaped leaves that are often appressed to the branchlets, as in juniper (Juniperus).

Scale-like: (2) [Petals, Phyllaries, Sepals] {shape} Having the form of small, often triangular shaped, leaves that are appressed to the branchlets, as in juniper (Juniperus).

Scale-like (3) : [Stipules] {type} In the form of a small, flattened structure, usually thin, dry and membranous in texture.

Scaly: [2-4-year-old twigs, Petioles, Rachises] {special surface features} Bearing scales of one kind or another.

Scarious: [Stipules] {type}

Schizocarp: [Fruits] {type} A dry fruit with two or more interior chambers (locules), splitting open (dehiscing) along the partitions between chambers and separating into indehiscent, usually one-seeded segments (mericarps), as in the carrot family (Apiaceae) and Acer.

Scorpioid cyme: [Inflorescences] {type} A cyme in which the lateral branches develop on only one side, each successive segment branching on the side opposite the previous one, producing a more or less zig-zag effect.

Scurfy: Covered with small, bran-like scales.

Secondary vein: A vein in a leaf or other laminar structure that branches from a main or primary vein; a side vein.

Sedges: Members of the Cyperaceae (Sedge family) are collectively known as 'sedges,' although some groups of plants in this family have other common names. The term 'sedge' is used to describe Carex spp. in particular

Seed: A mature or ripened ovule.

Seed Capsule: This consists of the exterior wall and inner cells (if any) of the ovulum (the base of a pistil) after they have become dried out. The seed capsule contains one or more mature or nearly mature seeds. The seed capsule is often ovoid in shape and more or less open at the top, although there are many variations in form

Seed coat: the outer protective covering of a seed that is developed from one or more integuments often in combination with other adherent parts of the ovary (as in a caryopsis)

Seed cone: A female or ovule-producing cone; typically larger and persisting longer than pollen cones.

Seedpod: This is a more or less spongy fruit that contains one or more seeds, often in rows; it often splits apart along one or two sides to release the seeds. Seedpods have variable shapes; in the Brassicaceae (Mustard family), they are often long and cylindrical, while in the Fabaceae (Bean family), they are often flattened and oblong.

Semicircular: [Leaf cross section] {shape} Shaped like a half circle in cross section.

Semi-evergreen: [Leaves] {duration} Bearing green leaves into or through the winter, but dropping them by the beginning of the next growing season; tardily deciduous or winter deciduous.

Semi-persistent: [Seed cones] {persistence} With some cones remaining on the branch after shedding seeds.

Sepal: A unit or segment of the outermost floral envelope or calyx of a flower; usually green and leaf-like.

Sepaloid: resembling or having the nature of a sepal

Septate: This describes leaf blades with cross-sectional venation that span adjacent parallel veins. Some Scirpus spp. (Bulrushes) have septate leaves with cross-sectional venation

Septicidal: dehiscent longitudinally at or along a septum

Septicidal capsule: [Fruits] {type} A capsule that splits open (dehisces) lengthwise along lines formed by the septa or the partitions separating chambers (locules) inside the ovary.

Septifragal: breaking from the partitions -- used of dehiscence in which the valves of a capsule or pod break away from the dissepiments

Septum (plural septa) : A distinct wall or partition that separates the chambers or locules of an ovary, fruit or other structure.

Sericeous: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} With long, silky, usually appressed hairs.

Serotinous: [Seed cones] {serotiny} Having cones that remain closed long after the seeds are ripe.

Serotiny: The tendency of some seed cones to remain closed long after the seeds are ripe.

Serrate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} Toothed along the margin, the sharp teeth pointing forward; sawtoothed.

Serrulate: [Leaf margins, Leaflet margins] {form} Toothed along the margin with very small, sharp, forward-pointing teeth; finely serrate or small-sawtoothed.

Sessile: [Flowers, Leaflets, Leaves, Seed cones] {form of attachment} Without a stalk, positioned directly against the bearing structure.

Seta: the slender stalk of the sporogonium of a bryophyte e : one of the stalked glands on plants of the genus Rubus f : the bristle in the utricle of some plants of the genus Carex

Shallowly lobed: [Leaflets, Leaves, Petals, Sepals] {lobing} With lobes that are cut approximately  to < the distance to the midrib or base.

Sheath: (1) : the lower part of a leaf (as of a grass) that more or less completely surrounds the stem (2) : an ensheathing spathe (3) ocrea

Sheathing: [Leaf bases, Leaflet bases] {shape} Having a tubular structure partially or completely enclosing the stem below the apparent point of attachment of the leaf blade or stalk (petiole).

Shoot: 1) The portions of a plant that are anatomically distinct from the root and differentiated into nodes, where leaves and branches originate, and the spaces in between (internodes); shoots consist of stems, leaves and any other structures borne from the stem.

Short shoot: A stumpy, slow growing, lateral branch with very short internodes, often bearing flowers; a dwarf shoot.

Shreddy: [Bark of mature trunks] {surface appearance} Soft but coarse, fibrous bark, usually shallowly furrowed, as in eastern red cedar (Juniperus virginiana).

Shrub: [Plants] {habit} A relatively short, woody, perennial plant, usually without a single stem or trunk, and often with many crowded branches.

Silicle: [Fruits] {type} A dry fruit that splits open (dehisces) along two sutures, the exterior walls eventually falling away in two halves, leaving a single, persistent, interior partition (septum) to which the seeds are attached; usually not more than twice as long as wide; common in the mustard family (Brassicaceae).

Silique: [Fruits] {type} A dry fruit that splits open (dehisces) along two sutures, the exterior walls eventually falling away in two halves, leaving a single, persistent, interior partition (septum) to which the seeds are attached; usually at least twice as long as wide; common in the mustard family (Brassicaceae).

Simple: [Leaves] {complexity} Undivided, as a leaf blade that is not separated into distinct leaflets; not compound. [modified from H&H, p. 156]

Simple dichasium: [Inflorescences] {type} A determinate, cymose, three-flowered inflorescence composed of a main stalk bearing a terminal flower and a pair of opposite or nearly opposite lateral flowers.

Simple ovary: An ovary composed of only one carpel; recognizable by the presence of only one area of placentation, locule, ovary lobe, style (or style branch), and stigma.

Simple umbel: [Inflorescences] {type} An inflorescence composed of several branches that radiate from almost the same point, like the ribs of an umbrella, each terminated by one or more flowers, the upper surface of the whole inflorescence rounded, or more or less flat.

Single scale: [Bud scales] {type} Covered by a single scale.

Sinuate: [Leaf margins, Leaflet margins, Petal margins, Phyllary margins, Sepal margins] {form} With the margin smoothly and shallowly indented; wavy in a horizontal plane.

Sinus: The space or recess between two divisions or lobes of an organ such as a leaf or petal.

Smooth: (1) [Buds, Young twigs, Leaves] With an even surface; not rough to the touch.

Smooth: (2) [Bark of mature trunks] {surface appearance} Bark having a more or less continuous, even surface, with relatively few fissures or protrusions, as in (Fagus grandifolia).

Smooth (3) : [Apophyses] {texture} With an even surface, lacking keels, grooves or other surface features.

Solitary: [Inflorescences] {type}; [Needles] {presence of clusters or fascicles } Occurring singly and not borne in a cluster or group.

Sorus (pl. sori) : a cluster of reproductive bodies or spores on a lower plant : as a : a clump of sporangia on a fertile frond of a fern

Spadix: [Inflorescences] {type} An inflorescence with small, stalkless (sessile) flowers more or less embedded in a thick, fleshy, unbranched axis or rachis, the whole inflorescence subtended and sometimes partially enclosed by a specialized bract or spathe, as in Jack-in-the-pulpit (Arisaema triphyllum).

Spathe: An often large, sometimes colored and flowerlike bract subtending and sometimes partially enclosing an inflorescence, as in calla lily (Zantedeschia) or jack-in-the-pulpit (Arisaema triphyllum).

Spatulate: [Leaflets, Leaves, Petals, Phyllaries, Sepals] {shape} Broad and rounded near the apex with a narrower, long, tapering base; spatula-shaped or spoon-shaped.

Spike: [Inflorescences] {type} A usually indeterminate, elongate inflorescence with unstalked (sessile) flowers arranged singly along an unbranched axis or rachis.

Spikelet: [Inflorescences] {type} The basic unit of inflorescence in the sedges (Cyperaceae) and grasses (Poaceae) consisting of a spike of tiny flowers that lack petals, each subtended by scale-like bracts; spikelets are the ultimate subdivision in a typically more complex inflorescence.

Spine: A woody, sharp-pointed, modified leaf or leaf part.

Spinose: (1) [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} Ending in a rigid, tapering, sharp tip; bearing a spine at the apex.

Spinose: (2) [Stipules] {type} Modified into a woody, sharp-pointed structure, as a stipular spine.

Spiny or prickly: [Leaf margins, Leaflet margins, Phyllary margins, Sepal margins] {form} Bearing spines or prickles along the margin.

Spiny, prickly, thorny: [2-4-year-old twigs, Petioles, Rachises] {special surface features} Bearing spines, prickles or thorns.

Spiral: [Leaves] {insertion} Arranged along the stem in such a way that a line connecting the points of attachment would form a spiral; a form of alternate arrangement.

Sporangium: (pl. sporangia) A spore-bearing case or sac.

Spores: Spores are produced by ferns, horsetails, and other primitive plants. Spores resemble tiny seeds, but they lack food for the plant embryo. Because spores are easily carried aloft by the wind, they allow ferns and horsetails to reproduce asexually across considerable distances. However, some species of plants, e.g. Isoetes spp. (Quillworts), reproduce sexually by producing both male and female spores. Because the female spores are larger in size than the male spores, they are referred to as 'macrospores.'

Spotted [Leaf lower surface, Leaf upper surface] {color variegation} The color disposed in small spots.

Spreading: [Leaves, Petals, Phyllaries, Sepals] {vertical orientation} Extending outward horizontally, or upward at an angle between 90: to 45: relative to the bearing structure.

Spurred: [Petals] {shape}

Squarrose: [Phyllaries] {vertical orientation}

Stalk: A supporting axis or column that bears a structure at its apex and is usually narrower than the structure being borne, as the stalk of a flower or leaf.

Stalked: [Flowers, Seed cones] {form of attachment} With a stalk.

Stamen: The male reproductive organ in a flower that produces and releases pollen, composed of an anther usually borne on a stalk (filament).

Staminate: [Flowers] {gender} Having one or more functional stamens, but no functional pistils, making the flower unisexual and male.

Staminodium: an abortive or sterile stamen (as in the flowers of the genus Parnassia)

Stellate: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With hairs that branch from the base and resemble tiny stars.

Stem: The axis of a shoot, bearing leaves, bracts and/or flowers, and usually growing above ground, but sometimes specialized and growing underground (see bulb, corm, rhizome and tuber) or on the surface of the ground (see stolon); stems are differentiated into regions called nodes, where leaves and branches originate, and internodes.

Sterigma-bearing: [2-4-year-old twigs] {special surface features} With persistent leaf bases that remain on the twig after the leaf falls and appear as peg-like projections.

Stigma: The pollen-receptive region at the tip of a pistil.

Stinging: [Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With erect, usually long hairs, that produce irritation when touched, as in stinging nettle (Urtica).

Stipitate glandular: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Rachises, Sepals, Young twigs] {pubescence type} With stalked glandular hairs.

Stipule: A relatively small, typically leaf-like structure occurring at the base of a leaf stalk (petiole), usually one of a pair; stipules are sometimes in the form of spines, scales or glands.

Stipule scar: The scar remaining on a twig at the former place of attachment of a stipule.

Stolon: [Stems] {type} A slender horizontal stem, at or just above the surface of the ground, that gives rise to a new plant at its tip or from axillary branches.

Stoloniferous: A stoloniferous root system has above ground runners (stolons) that can produce new plantlets some distance away from the mother plant.

Strigose: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} With straight, stiff, sharp appressed hairs.

Striped [Leaf lower surface, Leaf upper surface] {color variegation} Longitudinal, or ertical, stripes of one color crossing another.

Strobilus: a conelike aggregation of sporophylls (as in the club mosses and horsetails) b : the cone of a gymnosperm

Strong: [Seed cone armature] {strength} With sturdy armature that is not easily broken.

Style: The more or less elongated portion of a pistil between the ovary and the stigma.

Subshrub: [Plants] {habit} 1) A shrub-like plant but with only the base composed of woody tissue, the herbaceous branches dying back at the end of each growing season 2) A very low shrub that sprawls on the ground; a trailing shrub.

Subtend: to occupy an adjacent and usu. lower position to and often so as to embrace or enclose (a bract ~ing a flower)

Succulent: [Plants] {habit} Juicy, fleshy and often thickened, as the stem of a cactus or the leaves of Aloe.

Superior: [Ovaries] {position} With the ovary not fused to any portion of a floral cup, the whorl of sepals and petals (perianth) and/or stamens (androecium) thus arising from beneath the ovary. (Compare with inferior and half-inferior.)

Superposed: [Buds] {position} Located directly above an axillary bud.

Swollen: protuberant or abnormally distended: Swollen node

Syconium: [Fruits] {type} A multiple fruit characteristic of the figs (Ficus) with an enlarged, hollow, flask-like structure that becomes fleshy at maturity and bears numerous tiny, dry fruits along the inner surface.

Symmetric: [Seed cones] {symmetry} Divisible into essentially equal halves along one or more planes.

Sympetalous: [Corolla] {fusion} With petals united, at least at the base.

Synoecious: [Plants] {distribution of gender} With all flowers or cones bisexual, i.e. bearing functional reproductive structures of both sexes. (Compare with dioecious and monoecious.)

Synsepalous: [Calyx] {fusion} With sepals united, at least at the base.

Return to Top of Botanical Terms.

T

Tap: [Roots] {type} An enlarged vertical main root that is noticeably larger in diameter than any attached lateral roots.

Tendril-bearing : [2-4-year-old twigs, Petioles, Rachises] {special surface features} With a slender, twining organ used to grasp support for climbing, as grape (Vitis) vines.

Tepal: any of the modified leaves making up a perianth

Terete: approximately cylindrical but usu. tapering at one or both ends

Terminal: (1) At the top, tip, or end of a structure.

Terminal: (2) [Inflorescences, Seed cones] {position} At the apex or tip of the stem.

Terminal (3) : [Buds] {position} At the apex or tip of the stem.

Ternate: In threes, as a leaf which is divided into three leaflets.

Tessellated [Leaf lower surface, Leaf upper surface] {color variegation} Color arranged in small squares, so as to have some resemblance to a checkered pavement.

Thorn: A woody, sharp-pointed, modified stem.

Three-angled: [Leaf cross section] {shape} More or less triangular-shaped in cross section.

Three-ranked: [Leaves] {habit} With leaves arranged in along the stem in three rows.

Thyrse: [Inflorescences] {type} An elongate, many-flowered inflorescence with an indeterminate main axis or rachis and numerous lateral branches, each in the form of a cyme, as in most lilacs (Syringa).

Thyrsoid: having somewhat the form of a thyrse

Tomentose: [Buds, Leaf lower surface, Leaf upper surface, Petioles, Phyllaries, Sepals, Young twigs] {pubescence type} With tangled woolly hairs.

Tracheid: a long tubular cell that is peculiar to xylem, functions in conduction and support, and is characterized by tapering closed ends which are not absorbed as in tracheae and by thickened strongly lignified walls which commonly have bordered pits

Tree: [Plants] {habit} A relatively tall, woody, perennial plant usually with a single stem (trunk) that bears branches.

Trichome: Any type of plant hair (except for root hairs).

Trifoliolate: [Leaves] {complexity form} Compound with three leaflets; three-leafleted or ternate.

Tripalmately compound: [Leaves] {complexity form} With three orders of leaflets, each palmately compound; three-times palmately compound.

Tripinnately compound: [Leaves] {complexity form} With three orders of leaflets, each pinnately compound; three-times pinnately compound.

Tripinnately lobed: [Leaves] {lobing form} With three orders of leaf lobing, each pinnately lobed; three-times pinnately lobed.

Tripinnate-pinnatifid: [Leaves] {complexity form} Three times pinnately compound with pinnatifid leaflets.

Triternate: [Leaves] {complexity form} With three orders of leaflets, each divided into threes or ternately compound; three-times trifoliolate.

Truncate: (1) [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} With the apex cut more or less straight across; ending abruptly, almost at right angles to the midrib.

Truncate: (2) [Leaf bases, Leaflet bases] {shape} With the base cut more or less straight across; ending abruptly, almost at right angles to the midrib.

Trunk: The aboveground, relatively stout, main stem of a tree; the bole.

Tuber: [Stems] {type} A solid, enlarged, horizontal, shortened stem, usually borne below ground and containing food reserves, as in potatoes (Solanum tuberosum).

Tubercle: This is a small bump or wart-like structure on the surface of a floral structure. This typically refers to the surface of an achene (seed), which may have a single tubercle, or its surface may be more or less covered with a multitude of minute tubercles. Sometimes 'tubercle' refers to the spore-bearing structures on horsetails and ferns, which often have a bumpy appearance.

Tuberculate: The granular-pebbly surface of a seed.

Tuberous: A tuberous root system consists of a loose collection of coarse roots that occasionally thicken into fleshy underground tubers. These tubers store water and energy for the plant. Occasionally, rhizomes develop from the tubers that can produce new plantlets.

Tussock: The dense mat of roots at the base of some plants push the ground upward to form a mound, which is called a 'tussock.' Such plants often have multiple stems that develop directly from the tussock; this includes some species of grass, sedge, and fern

Twig: The relatively small end portion of a woody branchlet; a small branchlet.

Two-angled: [Leaf cross section] {shape} More or less flat in cross section, with an upper and lower surface.

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U

Umbel: a racemose inflorescence that is characteristic esp. of the family Umbelliferae and has the flower stalks in a cluster arising from a common point at the apex of the main stalk and reaching approximately the same height and sometimes branching again to form secondary clusters

Umbellate: bearing, consisting of, or arranged in umbels   2 : resembling an umbel in form

Unarmed: [Seed cone scales] {armature} Without a hook, prickle or other sharply pointed structure on the end of the cone scale.

Undulate: [Leaf margins, Leaflet margins] {vertical disposition}; [Petal margins, Phyllary margins, Sepal margins] {form} With the margin undulating or wavy in a vertical plane.

Unifoliolate: [Leaves] {complexity form} A structurally compound leaf with a single leaflet, making it appear simple, the compound nature of the leaf evident by a distinct articulation in the leaf stalk, as in redbud (Cercis canadensis); one-leafleted.

Unilocular: With a single interior compartment or locule.

Unisexual: [Flowers] {gender} Having functional reproductive structures of only one sex in the flower or cone.

Unlobed: [Leaflets, Leaves, Petals, Sepals] {lobing} With no recesses or indentations in the margin, or with indentations extending less than  the distance to the midrib or base.

Utricle: [Fruits] {type} A more or less small, dry fruit that does not split open at maturity (indehiscent), with a thin bladder-like outer wall that is loose and free from the single seed.

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V

Valvate: [Bud scales] {type} With scales (usually two) meeting by the edges without overlapping.

Valve: Some seed capsules are divided into cells with rounded exterior walls. The protruding walls of these cells are often referred to as "valves." Thus, a 3-celled seed capsule with 3 protruding walls is "3-valved." This also refers to the shape of the ovulum (base of the pistil) when such cells are present.

Variably serotinous: [Seed cones] {serotiny} Having some cones that open when the seeds ripen and others that remain closed long after the seeds are ripe.

Variegated [Leaf lower surface, Leaf upper surface] {color variegation} The color disposed in various irregular, sinuous, spaces.

Vascular bundle: A strand of conducting tissues and associated cells within a stem or connected structure.

Vegetative: 1) Of, or relating to, the non-flowering parts of a plant. 2) Producing new plants asexually by the spread or fragmentation of sterile (non-reproductive) tissue, without the formation of seeds.

Velamen (pl. velamina) : the thick whitish or greenish multiseriate corky epidermis covering the aerial roots of an epiphytic orchid and consisting of compactly arranged nonliving cells capapble of absorbing water from the atmosphere

Vernation: the arrangement of foliage leaves within the bud

Verticil: a circle or whorl of similar body parts (as flowers about a point on an axis . . . )

Verticillaster: [Inflorescences] {type} A pair of axillary cymes arising from opposite leaves or bracts and forming a false whorl, as in many salvias (Salvia).

Vessel: a conducting tube in a vacscular plant formed in the xylem by the fusion and loss of end walls of a series of cells -- compare TRACHEID

Vestigial: relating to or being a vestige, [being] a small and degenerate or imperfectly developed bodily part or organ that remains from one more fully developed in an earlier stage of the individual, in a past generation, or in closely related forms

Villous: [Buds, Leaf lower surface, Leaf upper surface, Phyllaries, Sepals, Young twigs] {pubescence type} With slender curved or wavy, but not matted hairs.

Vine: [Plants] {habit} A perennial plant with long woody or herbaceous stems that are flexible (at least initially), and are supported by other plants or structures, or that trail across the ground.

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W

Warty: [Bark of mature trunks] {surface appearance} Bark with relatively small, scattered protuberances, as in southern hackberry (Celtis laevigata).

Weak: [Seed cone armature] {strength} With armature that tends to break easily.

Weed: an introduced plant growing in ground that is or has been in cultivation usu. to the detriment of the crop or to the disfigurement of the place : an economically useless plant : a plant of unsightly appearance esp : one of wild or rank growth

Whorled: [Leaves] {insertion} With three or more leaves positioned on the stem at the same level; three or more leaves occurring at each node.

Winged: [2-4-year-old twigs, Petioles, Rachises] {special surface features} Having one or more elongate, relatively thin protrusions or appendages that loosely resemble wings, as the twigs of winged elm (Ulmus alata).

Woody: (1) [Plants] {woodiness} With an aboveground shoot composed of relatively hard tissue that persists from one growing season to the next.

Woody: (2) [Seed cone scales] {type} Of or resembling wood, and thus relatively hard and dry.

Wrinkled: [Apophyses] {texture} With small folds or creases.


X

Xerophyte: a plant structually adapted for life nd growth with with a limited water supply esp. by means of mechanisms (as epidermal thickening, waxy or resinous coats, or dense pubescence) that limit transpiration or that provide for the storabe of water -- u sed both of desert plants and of those occupying environments (as salt marshes or acid bogs) where water absorption is impeded by excess salts or acids in solution

Z

Zoned: [Leaf lower surface, Leaf upper surface] {color variegation} The same as ocellated, but the concentric bands more numerous.

Zygomorphic: bilaterally symetrical specif: capable of division into esentially symmetrical halves by only onlongitudinal plane passing through the axis.