Click a letter to navigate to that letter below


Name Definition


Acuminate tapered to a sharp point with concave sides, as a leaf or sepal.
Acute tapered to a sharp point with straight sides.
Alternate arising singly at each node on a stem, as the leaves.
Anther the pollen-producing organ of the stamen; in
Ascending growing upward obliquely, as stems or flowers on a stem.


Basal growing at the base, as leaves at or near the ground.
Beard a tuft of hairs, as on the palate or staminode.
Blade the broad part of a leaf or petal.
Bract a leaf, usually reduced, in the inflorescence, from the axil of which a floral peduncle or pedicel may arise


Calyx the sepals of a flower collectively, the outermost portion of a flower.
Capsule a dry specialized seed pod, as in Penstemon.
Caudate with a sharp tail-like appendage, as on a leaf tip.
Caulescent with a leafy stem rising above ground.
Cauline of or pertaining to a leafy stem, bearing flowers in Penstemon.
Channeled a longitudinal groove, as a leaf folded along the midrib.
Clasping partly or wholly surrounding a stem, as the base of a leaf.
CM (Centimeter) 10 millimeters, 0.1 decimeter, 0.01 meter (approx. 13/32 inch).
Connate-perfoliate joined at the base and surrounding a stem, as a pair of leaves.
Connective the tissue joining two pollen sacs as in the stamens of Penstemon.
Cordate heart shaped.
Corolla collectively the petals of a flower; in Penstemon, joined at the base to form a tube and the petal lobes.
Cyme one peduncle of a branching inflorescence bearing two or more flowers with the terminal flower blooming first; in Penstemon, one side of a verticillaster.

Back to the top of this page.


Deciduous with leaves falling at the end of the growing season.
Declined curved or angled downward, i.e., below the horizontal
Decumbent a stem with a curving or reclining base and erect or ascending tip.
Dehiscent rupturing at maturity, as anther sacs or capsules.
Dentate with spreading or outward-pointing teeth on the margin.
Determinate as an inflorescence in which the terminal flower blooms first, stopping elongation of the peduncle or main stem.
Divergent spreading widely apart but not completely opposite, as the anther sacs in Penstemon.
dm (decimeter) 0.1 meter, 10 centimeters, approximately 4 inches.


Elliptic approximately the shape of an oval, as a leaf or sepal.
Elongate growing in length; considerably longer than wide.
Endemic growing in a confined area or geographic region.
Entire continuous, not toothed or cut, as a leaf margin.
Erose a ragged or irregularly cut margin.
Evergreen leaves remaining green over winter.
Exotic introduced; not native to a region.
Expanded enlarged, as the tip of a staminode.
Explanate spreading out flat, as dehiscent anther sacs.
Exserted protruding, as stamens or staminode from a corolla.


Fertile capable of reproduction, as a stamen bearing pollen.
Filament the stalk of a stamen supporting the anther.
Fleshy thick and succulent, pulpy.
Flexuous curved or bent, as a stem.
Foliage the leaves collectively.

Back to top.


Genus (pl. Genera) a group of structurally related species; a classification between family and species.
Glabrous a smooth surface; without hairs or glands.
Glandular bearing glands, as on the ends of hairs or on a surface.
Glaucous a fine waxy powder, usually blue or gray, covering a surface.
Guide Lines Pigmented veins in the throat or on the palate of a tubular corolla, as in Penstemon.


Herb a plant or that part of a plant dying back at the end of a growing season.
Herbaceous green colored, non-woody.


Incised deeply cut, as the teeth on a leaf margin.
Inclined angled upward, above horizontal.
Included enclosed within a structure, as the stamens within the corolla.
Indeterminate as an inflorescence in which the bottom flowers bloom first, so that the peduncle or main stem can continue to elongate.
Inflorescence the flowers collectively on a plant; the arrangement of flowers along a flowering stalk including side branches.



Back to top.


Keeled with a conspicuous longitudinal ridge, as on the top of a corolla.


Lanceolate Lance shaped.
Limb the expanded part of a corolla; from the basal tube to the throat in Penstemon.
Linear long and narrow with nearly parallel sides; like a line.
Lip the petals of a corolla aggregated into a shelf, as the upper and lower lips in Penstemon.


mm (millimeter) 0.001 meter, approximately 1/25 of an inch.
Mucronate with a short, sharp point at the tip, as a leaf or sepal.


Naturalized introduced into an area and wet established.
Nectar a sweet substance produced by a flower to attract pollinating insects; a nectary is the structure that produces nectar
Node the point of attachment of a leaf bract or branch on a stem.

Back to top.


Oblanceolate reverse lance-shaped, attached at the narrow end and enlarged at the outer end.
Oblong longer than broad with nearly parallel sides, as a leaf.
Obtuse broad at the tip, the sides forming an angle greater than 90 degrees.
Opposite located directly across from each other, as two leaves on a stem or the sacs of a dehiscent anther.
Orifice the mouth or opening of a corolla tube; the throat.
Ovary the expanded base of the pistil; the structure that contains developing seeds in plants.
Ovate broadly elliptic or egg-shaped, as the leaves.


Palate raised portion(s) of the lower lip of the corolla, tending to constrict the throat.
Panicle a branched inflorescence that blooms from the bottom upward.
Pedicel the stalk of a single flower in an inflorescence.
Peduncle the stalk of a cyme or inflorescence or of a single flower.
Petiole a leaf stalk or narrow leaf base.
Pistil the female organ of a flower, typically composed of stigma, style and ovary.
Pollen sacs in Penstemon, a pair of pollen sacs constitutes an anther.
Prostrate lying flat on the ground
Pubescent with hairs of any sort; herein generally hairs without glands.




Raceme an unbranched inflorescence with each flower on an individual pedicel attached to the main axis, blooming from the bottom upward.
Reclined bending or angled downward; lying on some support, as the base of a stem lying on the ground.
Recurved curving or bent backward
Reduced Becoming smaller.
Remote spaced well apart; small in size.
Revolute rolled backward or under, as margins.
Rhizome a horizontal underground stem or rootstock
Robust vigorous, often above average in size
Rosette a cluster of leaves, usually encircling the base of a plant
Rotund round, plump.

Back to top.


Sacs pouches, see pollen sacs
Sagittate in the shape of an arrow or arrowhead
Scarious thin and white, as the margin of a sepal.
Secund arranged on one side of a main stem, as an inflorescence.
Sepals outermost floral leaves; segments of the calyx.
Serrate like saw teeth; forward-pointing teeth on the margins.
Sessile directly attached at the base, as a leaf without a petiole.
Shoots young or short stems or branches. Uses a gun, as pointing at deer in garden.
Shrub a plant with several stems, woody at the base, not dying back at the base.
Spatulate spatula-shaped, broad and rounded at the end and tapered to a narrow base, as a leaf.
Species a plant that possesses one or more unique characteristics; a classification between genus and variety (subspecies).
Spike an unbranched inflorescence with sessile flowers on the main axis.
Spreading expanding to nearly horizontal branches, as an inflorescence.
Stamen the male, pollen-producing organ of a flower, normally composed of a filament and an anther.
Staminode a modified sterile stamen producing no pollen.
Stem an axis of a plant bearing nodes, leaves and buds, usually above ground.
Sterile not fertile, not producing seeds or pollen; stems without flowers.
Stigma that portion of the pistil on which pollen is deposited, normally the end of the style, often enlarged.
Style the usually slender stalk connecting the stigma and ovary.
Sub a prefix meaning "almost" or "not quite," as in subequal and subshrub.
Suture a line of fusion or separation, as in the dehiscence of an anther or capsule.


Throat the opening or orifice of a corolla.
Thyrse a densely compact inflorescence; a panicle with indeterminate main axis and cymose branches.
Toothed dentate; having lobes or points along a margin.
Truncate with the end squared off or abruptly rounded as if cut off.
Tubular with the form of a cylinder.

Back to top.


Umbel an inflorescence in which 3 or more pedicels arise from a common point on a stem.


Valve in an anther, one side of the anther wall after dehiscence. variety—a classification in taxonomy below the species level.
Verticillaster a false whorl; in Penstemon, arising at a node and composed of 2 cymes (a branched cluster of blooms that looks like a whorl).
Villous with long, soft hairs.


Whorl a ring of 3 or more leaves or flowers arising from a common node or point.







Back to top.