Plant Glossary
Achene	A non-fleshy, 1-seeded fruit.
Alternate	Type of leaf arrangement in which only a single leaf is attached at each node. Term may also apply to other plant structures attached one per node.
Annual	A plant with a 1-year life cycle, growing from seed, producing flowers and fruits, and dying in 1 year.
Anther	The pollen-bearing part of the stamen.
Appressed	Lying close and flat against another part.
Auricle	A small projecting lobe or appendage, as found at the base of leaf blades of some species of the grass family (Poaceae).
Awn	A slender bristle-tip.
Awnless	Lacking an awn.
Axil	The point of the angle between the stem and leaf attachment.
Banner	The enlarged upper petal of a flower of the pea family (Fabaceae).
Basal	Related to, or located at the base.
Beak	A prolonged, usually narrowed tip of a thicker structure, as in some fruits and petals.
Beaked	Ending in a beak.
Biennial	A plant that lives for two growing seasons, usually flowering only in the second year.
Bilateral (symmetry)	Divisible into identical halves in only one plane; found in "irregular" flowers such as orchids.
Blade	The expanded, flattened part of a leaf or petal.
Bract	A reduced leaf subtending a flower, usually associated with the inflorescence.
Bristle	A hair-like structure; in members of the sunflower family (Asteraceae), it refers to one type of pappus, while in certain members of the sedge family (Cyperaceae) it refers to reduced perianth parts.
Bulb	A short, vertical underground shoot which has modified leaves or thickened leaf bases developed as food storage organs.
Bulbil	A small bulb.
Calcareous	Referring to limestone or lime-rich soils.
Callus	A firm thickening, like the thickened base of the lemma of many grasses (Poaceae).
Calyx	Outer whorl of flowering parts, collective term for all the sepals of a flower, (plural = calyces).
Capsule	A dry fruit that opens by slits, lids, pores, or teeth to release seeds.
Catkin	An inflorescence composed of an often drooping, or pendulous, cluster of unisexual, petal-less flowers, typical of wind pollinated trees and shrubs, such as willows, cottonwoods, oaks, and birches; also called an ament.
Chaffy	Covered by thin, dry scales.
Clasping	Leaf base partly or wholly surrounding the stem.
Cobwebby	With the appearance of spider webbing, usually referring to very fine hairs.
Column	A group of united filaments.
Compound (leaf)	A leaf divided into leaflets.
Congested	Crowded, as in an inflorescence with many densely clustered flowers.
Connate	Grown together or attached in a circle.
Contracted	Narrowed in a particular place.
Corolla	Collective term for all the petals of a flower, these petals may be separate or fused together.
Cotyledon	A leaf of the embryo of the seed.
Deciduous	Falling off; not permanent or evergreen.
Decumbent	Resting on the ground, but with the tip rising up (in contrast to prostrate, in which a structure lies completely flat on the ground).
Dehiscent	Splitting open along regular lines, as in a fruit or anther.
Disk	The tubular flowers found at the center of the flower head of many members of the sunflower family (Asteraceae).
Dolabriform (hair)	Pick-shaped; attached along the middle.
Ecotype	Genetically distinct individuals of a species that are adapted to a particular environment.
Elliptic	Oval shaped, with the ends rounded and the widest point at the middle.
Entire	Undivided; in leaves; having even-edged leaf margins rather than incised or toothed.
Erect	Upright in relation to the ground.
Evergreen	Bearing green leaves or stems over the winter; not deciduous.
Farinose	Covered with a meal-like powder.
Fertile	Bearing or producing reproductive structures.
Fibrous (roots)	Roots with several to many more or less equal branches; lacking a large central taproot.
Filiform	Very slender, threadlike.
Flaccid	Weak and lax.
Frond	The leaf of a fern.
Fruit	The ripened, seed-containing reproductive structure of a plant.
Galea	Upper lip enclosing the anthers in the paintbrush genus (Castilleja)
Gametophyte	The generation which has n chromosomes and produces gametes as reproductive bodies.
Glabrous	Without hairs.
Gland	A depression or appendage which usually secretes a sticky fluid.
Glandular	Bearing glands.
Glaucous	Covered with a waxy coat, often whitish or bluish in color.
Glumes	The pair of bracts at the base of a grass spikelet.
Head	A dense cluster of flowers, usually nearly spherical in outline. Individual flowers in the head are usually sessile or nearly so.
Herbaceous	Non-woody; dying to the ground each year.
Hood	Erect or spreading petal-like blade with incurved margins in the milkweed family (Asclepiadaceae).
Horn	An appendage extending from the hood in the milkweed family (Asclepiadaceae).
Indusium	A covering over the cluster of sporangia in many ferns.
Inflated	A structure that is bladdery or expanded like a balloon.
Inflorescence	The flowering part of a plant, usually referring to a cluster of flowers on a single stem.
Inrolled	Curled or curved inwards; involute.
Internode	The portion of a stem between two successive nodes, the gap between successive points of attachment of leaves on a stem.
Interrupted	Discontinuous; in an inflorescence, having clusters of flowers interspersed with bare areas of stem.
Involucre	A whorl of bracts located beneath (subtending) a flower cluster, as in the heads of members of the sunflower family (Asteraceae).
Keel	A prominent ridge shaped like the keel of a boat; in some members of the pea family (Fabaceae) referring to the lower, boat-shaped petal of the flower that encloses the ovary and stamens.
Lacerate	With an irregularly-jagged margin.
Lanceolate	Lance-shaped, much longer than broad and tapering to a tip.
Lateral	On or at the side.
Leaflet	Any subdivision of a compound leaf.
Lemma	The larger of the two bracts (the other being the palea) that enclose the stamens and pistil in a grass floret.
Ligule	Membranous structure or fringe of hairs found at the junction of the leaf blade and sheath of grasses.
Linear	Several times longer than wide, usually refers to very narrowly shaped leaves or fruits.
Lip	The lowermost, often highly modified, petal of some flowers as in orchids, mints, and penstemons.
Lobe	A division or segment of a structure, usually rounded in outline.
Margin	An edge, as in the edge of a leaf blade.
Mealy	Soft, dry, and crumbly textured, as in certain fruits.
Membranous	Thin, soft, and pliable.
Midrib	The main, central vein of a leaf, bract, scale, or petal.
Mucilaginous	Slimy.
Node	The point of attachment of a leaf or leaves on a stem; the joint of a stem.
Nutlet	A small, one-seeded, nut-like structure; the specialized fruit of members of the borage (Boraginaceae) and mint families (Lamiaceae).
Oblanceolate	A structure that is broadest near the tip and tapering to a narrower base.
Oblong	Much longer than broad, with nearly parallel sides; wider than linear.
Once-pinnate	A compound leaflet divided into entire leaflets (the leaflets are not further divided into lobes or secondary leaflets).
Opposite	Type of leaf arrangement in which two leaves are attached on opposite sides of a stem at the same node.
Ovary	The part of the pistil of a flower that contains the ovules.
Ovate	Egg-shaped, with the broadest end toward the base.
Palea	The smaller of the two bracts (the other being the lemma) that enclose the stamens and pistil in a grass floret.
Palmate	Lobed or veined with 3 or more branches or veins arising from a common point, like the fingers of a hand.
Panicle	A much-branched inflorescence in which the central axis (main stem) bears flowering branches which are themselves branched again.
Pappus	The modified sepals (calyx) of members of the sunflower family (Asteraceae) found at the top of the fruit in the form of thin bristles, feather-like plumes, scales, or sharp awns.
Partition	Line separating the two halves of the fruit of a mustard (Brassicaceae).
Pectinate	Resembling a comb in having very narrow parallel segments borne at a right angle to the main axis.
Pedicel	The stalk of a single flower in a flower cluster, a single fruit, or a single grass spikelet.
Peduncle	The stalk of a flower or flower cluster.
Perennial	A plant which lives for three or more years.
Perianth	Collective term for the calyx and corolla of a flower.
Pericarp	The wall of the fruit.
Perigynium	Sac-like structure enclosing the fruit in species of the cyperus family (Cyperaceae). Plural = perigynia.
Persistent	Remaining attached, as in the calyx on a fruit or remnant, dead leaves.
Petal	The usually colored, individual components of the corolla of a flower.
Petiole	A leaf stalk.
Pinnae	One of the primary divisions of a compound leaf.
Pinnate	With leaflets, lobes, or veins originating from several different points on each side of a main axis, as in the structure of a feather.
Pinnately compound	Division of a leaf blade into leaflets arranged on each side of a common leafstalk.
Pistil	The ovule-bearing structure of a flower, consisting of a stigma, style, and ovary; the "female" part of a flower.
Pistillate	With pistils, but lacking stamens; "female".
Plumose	Feathery.
Pod	Any dry, dehiscent fruit, such as that of many members of the pea family (Fabaceae).
Prostrate	Lying flat upon the ground (in contrast to decumbent in which a structure lies flat on the ground except for the tip which rises upward).
Pubescence	Any type of hair-like structure on a plant part.
Pubescent	Having hairs.
Raceme	An elongate inflorescence made up of stalked flowers attached directly to the main axis.
Rachis	A main axis, such as that of a compound leaf.
Ray	The strap-like flowers at the margin of a head in members of the sunflower family (Asteraceae); a primary branch of the inflorescence in members of the parsley family (Apiaceae).
Recurved	Curved downward or backwards.
Reflexed	Abruptly bent downward or back.
Reticulate	Forming a network pattern.
Rhizomatous	Bearing rhizomes.
Rhizome	An underground stem or rootstock bearing reduced, scaly leaves.
Rib	Prominently raised vein or wing-like structure.
Rootstock	Slow-growing, woody upright underground base of a perennial herb that gives rise to yearly growth of stems and leaves; caudex.
Rosette	A crowded cluster of leaves located at, or near the ground, at the base of a stem.
Runner	A slender stolon.
Scabrous	Rough to the touch like sandpaper, usually due to very short, stiff hairs or outgrowths of the epidermis.
Scale	Any thin, short, often membranous structure; in the sedge family (Cyperaceae) often used in reference to the bracts that subtend individual staminate and Distillate flowers; small, sharp-tipped leaves of certain clubmosses (Lycopodiaceae).
Secund	Oriented on one side of an axis, as in fruits or flowers all being on one side of a stem.
Sepal	An individual leaf-like segment of the calyx of a flower.
Sessile	Lacking a stalk, attached directly at the base (as in a leaf without a petiole).
Sheath	The lower part of the leaf that enfolds the stem in grasses, sedges, and rushes; in horsetails (Equisetum) used to describe the ring of papery leaves at each stem joint.
Shrub	A woody plant with several equally large stems from the base, usually less than 4.5 m tall.
Silique	A fruit type found in certain members of the mustard family (Brassicaceae) characterized by its long, slender shape that is typically 3 or more times longer than wide.
Simple	Unbranched or undivided; in leaves refers to condition in which leaves are not divided into leaflets.
Sorus	A cluster of sporangia (plural=sori).
Spike	An elongated inflorescence of sessile flowers or florets.
Spikelet	The basic unit of the inflorescence of grasses and sedges. In grasses (Poaceae), it is composed of a pair of basal glumes subtending 1 or more florets. In sedges (Cyperaceae) it consists of a single bract subtending a flower.
Sporangium	A case or container for spores (plural=sporangia).
Spore	The reproductive body produced and dispersed by ferns, horsetails, club mosses and other "lower" vascular plants that do not reproduce by true seeds.
Sporophyll	A leaf which bears or subtends 1-more sporangia.
Spreading	Diverging at nearly a right angle from a structure; nearly prostrate.
Spur	A tubular or sac-shaped extension of a petal or sepal.
Stamen	The pollen-producing structures of a flower; the "male" part of a flower.
Staminate	With stamens, but lacking a pistil; "male".
Staminode	A modified stamen which does not produce pollen.
Sterile	Non-fertile; structure lacking reproductive parts or abilities.
Stigma	The surface of the pistil on which pollen grains land and germinate.
Stipule	Leaf-like or scaly appendages (typically paired) at the base of the petiole in many plants. These may be fused at the base as in some members of the pea family (Fabaceae).
Stolon	A horizontal stem, usually growing along the surface of the ground, often giving rise to new plants at its tip; runner.
Strobilus	Cone-like reproductive structure; spore-bearing structure of horsetails (Equisetaceae) and clubmosses (Lycopodiaceae; plural = strobili.)
Style	The portion of the pistil between the ovary and the stigma.
Subtend	To be situated immediately below, as in bracts beneath a flower.
Taproot	The primary root from which secondary (smaller, lateral) roots arise.
Tendril	A slender, coiling or twining organ by which a plant clings to a support.
Tepal	A segment of the perianth not clearly differentiated between sepals and petals.
Terminal	Located at the tip of a structure.
Ternately compound	Divided into threes, as in a leaf consisting of three leaflets.
Tooth	Any small, marginal lobe, usually on the edge of a leaf blade.
Tufted	A close-growing cluster of stems, as in certain bunchgrasses, sedges, and mat-forming herbs.
Tussock	A compact, densely tufted growth form of some grasses and sedges.
Twig	The current year's growth of a woody stem; the endmost section of a branch.
Umbel	A flower cluster in which the individual flower stalks arise from a common point, like the rays of an umbrella.
Valve	One of the segments into which a dehiscent fruit separates.
Vegetative	A sterile structure of a plant, not associated with the production or dissemination of seeds, spores, or pollen.
Vein	A vascular bundle of a leaf or petal; nerve.
Viscid	Sticky; with sticky exudates.
Whorl	a ring of 3-more similar structures radiating from a common point.
Wing	A thin, often dry or leaf-like extension bordering a structure; also referring to the 2 lateral petals of the flower in some members of the pea family (Fabaceae).
Woolly	with long, interwoven hairs.