- Acaulescent
The leaves clustered at or near the base of the plant. - Achene
A small, dry, 1-seeded indehiscent fruit. - Acuminate
Gradually tapering to the apex. - Acute
Tapering to the apex with straight sides. - Alkaline
Having the properties of an alkali; a pH of more than 7. - Alluvium
Clay, silt, sand, gravel, or similar detrital material deposited by running water. - Alternate
Borne singly, not opposite. - Androgynous
Having staminate flowers above the carpellate flowers. - 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 a stamen. - Anthesis
Period when the flower is open. - Apetalous
Having no petals. - Apex
Uppermost point. - Appressed
Lying close to or flat against. - Areole
The point at which a cluster of spines arises; equivalent to a node (Cactaceae). - Arroyo
The channel of an ephemeral stream in an arid region. - Auricle
An ear or flap-like appendage at the summit of the leaf sheath in grasses. - Awn
A slender, bristle-like structure; the tips of glumes and lemmas on some grasses. - Axil
Angle formed by a leaf with the stem to which it is attached. - Axillary
In axil of leaf, branch, or other structure. - Banner
The broad, erect, upper petal of the flower of legumes (Fabaceae). - Basal
Leaves produced at ground level. - Basifixed
Attached at the base, as anthers to the filament. - Beak
A hard or firm point of projection. - Bi
Prefix meaning two or twice. - Biennial
A plant that lives for two growing seasons, usually flowering only in the second year. - Bisexual
A flower having both stamens and pistils. - Blade
Flat, expanded portion of leaf or petal. - Bract
Reduced or modified leaf. - Bractlet
A secondary bract, usually smaller than the bracts. - Bristle
Short, stiff, coarse hair or filament. - Bulb
Underground bud covered with fleshy scales. - Caespitose
Growing in tufts or clumps. - Calcareous
Referring to limestone or calcium-rich soils. - Callus
Hardened base of the lemma in some grasses. - Calyx
The collective name for sepals. - Campanulate
Bell-shaped. - Capillary
Thread-like. - Capitate
Collected into a dense, head-like cluster. - Capsule
A dry, dehiscent fruit made up of more than one carpel. - Carpel
One of the female reproductive organs of a flower, i.e. a unit of the gynoecium, comprising an ovary (containing 1 to many ovules borne on a placenta) and with a usually terminal style tipped by the stigma. - Carpellate
Having carpels. - Carr
A wetland willow thicket. - Catkin
A spike or spike-like inflorescence of unisexual flowers. - Caudex
The persistent, often woody base of an otherwise herbaceous stem.
Plural = caudices. - Cauline
Leaves borne on the stem, above ground. - Ciliate
With a marginal fringe of hairs. - Cinereous
With grey or white pubescence that creates an ashy look. - Circumboreal
Distributed around the high latitudes of the northern hemisphere in the boreal zone. - Clasping
Leaf base partly or wholly surrounding the stem. - Claw
The narrow base or stalk to some petals. - Cleft
Split about in the middle. - Cobwebby
With the appearance of spider webbing, usually referring to very fine hairs. - Compound (leaf)
A leaf divided into leaflets. - Congested
Crowded, as in an inflorescence with many densely clustered flowers. - Connate
United, usually by fusion or pressure in the bud. - Contracted
Narrowed in a particular place. - Cordate
Heart-shaped. - Corolla
Collective name for the petals. - Cruciform
Cross-shaped. - Culms
The specialized stem of grasses, sedges and rushes. - Cyme
A flower cluster, usually opposite-branched, in its simplest form consisting of three flowers, the central or terminal one blooming first. - Deciduous
Falling off; not permanent or evergreen. - Decumbent
Prostrate except for the ascending tips of branches. - Decurrent
Extending downward along stem or branch from the point of insertion. - Dehiscent
Splitting open along regular lines, as in a fruit or anther. - Deltoid
Triangular. - Dentate
Toothed, with the teeth directed outward rather than forward. - Dilated
Expanded or widened. - Dioecious
Having staminate and pistillate flowers on separate plants of a species. - Dimorphic
Two forms. - Disjunct
Separated from the main, continuous portion of a species’ range. - Disk flower
The tubular flowers found at the center of the flower head of many members of the sunflower family. - Dissected
Divided into many segments or lobes. - Divaricate
Widely spreading. - Dorsal
Pertaining to the back or outer surface. - Dorsiventral
With an upper and lower side (flattened from the back rather than the sides). - Duff
Organic matter on the forest floor. - Elliptical
Shaped like an ellipse: widest in the center and the 2 ends equal. - Endemic
Restricted to a particular geographic region or soil type. - Entire
Margins without teeth or lobes. - Ephemeral
A plant that completes its life cycle very rapidly.
In favorable environments ephemerals may germinate, bloom, and set seed several times during a single year. - Epicarp
Outer layer of the fruit, the “skin”. - Erect
Upright in relation to the ground. - Evergreen
Bearing green leaves or stems over the winter; not deciduous. - Exfoliate
To come off in thin sheets. - Explanate
Spread out flat, as opened anthers. - Exserted
Projecting beyond a surrounding organ. - Farinose
With a mealy or powdery covering of wax. - Fellfield
Type of tundra that is thirty-five to fifty percent bare rock, with cushion plants, mosses, and lichens between. - Fen
An area of wet peat that is typically alkaline due to ground water draining from surrounding calcareous rocks. - Fertile
Capable of producing fruit or spores. - Fibrous (roots)
Roots with several to many more or less equal branches; lacking a large central taproot. - Filiform
Thread-like. - Flaccid
Soft and limp; drooping or hanging. - Flexuous
Wavy or curved. - Floret
A small flower, especially one in a dense cluster.
Also used for a grass flower with its lemma and palea included. - Flower
Reproductive structures of plants. - Follicle
A type of dry fruit derived from a single pistil that splits open along only one suture line, as in milkweed pods. - Fornix
A scale or gland-like protuberance in the flower tube, as in the Boraginaceae. Plural = fornices. - Frond
Leaf of a fern. - Fruit
The ripened, seed-containing reproductive structure of a plant. - Funiculus
The stalk attaching the ovule or seed to the wall of the ovary (plural = funiculi); a structure of diagnostic value for Physaria spp. (Brassicaceae). - Glabrate
Almost glabrous. - Glabrous
Without hairs. - Gland
A depression or appendage which usually secretes a sticky fluid. - Glandular
With organs which produce small droplets of secretion, often at tips of hairs. - Glaucescent
Slightly glaucous. - Glaucous
A whitish wax-like covering. - Globose
Spherical. - Glume
A bract at the base of a grass spikelet. - Gneiss
Coarse-grained, banded metamorphic rock in which minerals are arranged in darker and lighter layers. - Graminoid
Grass-like. - Granite
Light-colored, coarse-grained igneous rock. - Granodiorite
Granular intrusive quartz igneous rock, intermediate between granite and diorite; a quartzose diorite. - Gynaecandrous
In Carex, pistillate flowers above staminate flowers. - Gynoecium
Collective name for the pistils. - Gypsiferous
Bearing gypsum (hydrous calcium sulfate). - Habitat
The part of the environment where a plant grows. - Head
A dense cluster of flowers, usually nearly spherical in outline. Individual flowers in the head are usually sessile or nearly so. - Helicoid
Curled in the form of a spring or snail shell. - Herb
A plant with no persistent woody stem above ground. - Herbaceous
Non-woody; dying to the ground each year. - Hirsute
With coarse, straight hairs. - Hispid
Clothed with stiff bristles or bristle-like hairs, usually stiff enough to penetrate the skin. - Hood
Erect to spreading petaloid blade with incurved margins (Asclepiadaceae). - Hummock
Small mound. - Hyaline
Transparent or translucent. - Hypanthium
Cup or tube formed by the fused bases of the stamens, petals, and sepals. - Igneous
Rock that was crystallized from a magma. - Imbricate
Overlapping like shingles. - Incised
Cut sharply and usually irregularly with sharp sinuses. - Incurved
Curved toward the axis or attachment. - Indehiscent
Not splitting open at maturity. - Indusium
A membranous flap covering the sorus of ferns.
Plural = indusia. - Inferior
Located beneath or lower than another structure, as in the ovary of a flower located beneath the sepals and petals. - 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. - Intermittent
Not continuous. - Internode
Portion of a stem or other structure between 2 nodes. - Involucre
A whorl of bracts located beneath a flower cluster, as in the heads of members of the sunflower family (Asteraceae, Polygonaceae). - Involute
Having edges rolled inward, like a scroll, toward the midnerve on the upper surface. - Keel
A projecting central rib or dorsal ridge, like the keel of a boat. - Lanceolate
Lance-shaped; several times longer than wide, broadest toward the base and tapering to the apex. - Lateral
Refers to the side, as opposed to dorsal. - Leaf
Thin, usually green, expanded organ borne on a node of a stem. - Leaflet
One of the divisions of a compound leaf. - Lemma
In grasses, the lower of two bracts enclosing the floret. - Ligule
A hair-like or membranous projection up from the inside of a grass sheath at its junction with the blade. - Limb
Expanded and spreading part above the throat, in a corolla with united petals. - Linear
Narrow and flat with the sides parallel, like a grass leaf blade. - Lip
The lowermost, often highly modified, petal of some flowers (such as orchids, mints, and penstemons). - Loam
Class of soil texture composed of sand, silt, and clay, which produces a physical property intermediate between the extremes of the three components. - Lobe
A division or segment of a structure, usually rounded in outline. - Locule
Compartment or chamber of an ovary. - Marcescent
Persisting beyond a single season as dried parts. - 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. - Monomorphic
One form. - Monoecious
Having the stamens and carpels in different flowers on the same plant. - Montane
Relating to the biogeographical zone of relatively moist cool slopes below timberline dominated by large evergreen trees. - Mucro
Minute and abrupt point at the apex. - Mucronate
With a mucro. - Node
A joint or point of attachment for leaves or branches. - Nutlet
Hard, small, indehiscent, one-seeded fruit. - Ob
A prefix implying the reverse. - 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. - Obtuse
Blunt or rounded at the apex. - Ochroleucous
Off-white, buff. - 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. - Orbicular
Circular in outline. - Ovary
The part of the pistil of a flower that contains the ovules. - Ovate
Egg-shaped, (two-dimensional) with the broadest end toward the base. - Ovoid
Egg-shaped (three-dimensional). - Ovules
Structure that develops into the seed. - Pagodaeform
Shaped like a pagoda. - Palea
The smaller of the two bracts (the other being the lemma) that enclose the stamens and pistil in a grass floret. - Pallid
Deficient in color. - Palmate
With leaflets, lobes, or veins arising from the same point at tip of petiole. - Panicle
A compound inflorescence with two or more flowers on each branch. - Papilla(e)
A minute epidermal wart(s). - Pappus
An appendage at the apex of the ovary. - Partition
Line separating the two halves of the fruit of a mustard (Brassicaceae). - Peat
Highly organic soil often in bogs or fens. - 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 spiklet. - Peduncle
The stalk of an inflorescence. - Pendant
A structure that is allowed to hang free. - Pendulous
Hanging downward. - Perennial
A plant which lives for three or more years. - Perianth
Collective term for the calyx and corolla of a flower. - Perigynium
The inflated sac enclosing the ovary in species of Carex (Cyperaceae). Plural = perigynia. - Persistent
To remain unchanged or fixed in a specified condition. - Petal
The usually colored, individual components of the corolla of a flower; literally the leaves of a flower. - Petiole
The leaf stalk. - Petiolate
Having a petiole. - Phyllary
The involucral bract on the head of members of the sunflower family (Asteraceae). - Pilose
Covered with long, soft hairs. - Pinna(e)
One of the first or primary divisions of a pinnately compound leaf: usually used to describe ferns. - Pinnate
Compound leaf with the leaflets on 2 opposite sides of an elongated axis. - Pinnately compound
Division of a leaf blade into leaflets arranged on each side of a common leafstalk. - Pinnatifid
Pinnately lobed, cleft or parted 1 ¦2 way to the midrib or more. - Pinnatisect
Pinnately dissected. - Pinnule
A secondary division of a fern frond. - Pistil
The seed-producing organ, consisting of a stigma and ovary with a style between. - Pistillate
A flower which lacks well-developed, functional stamens. - Placenta
Any part of the interior of an ovary that bears ovules. - Playa
An inland drainage basin, surrounded by sheets of alkaline or saline crust and containing a shallow, often ephemeral lake. - Plumose
Hairs with side hairs along the main axis like the plume of a feather. - 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). - Puberulent
With very short hairs. - Pubescence
Hair on various parts of the plant. - Pubescent
Having hairs. - Pungent
Sharp-pointed, prickly to touch. - Pustulate
With wart-like elevations; hairs with an expanded or wart- like base. - Pustulose
Hirsute, with basally swollen hairs. - Raceme
An elongate inflorescence made up of stalked flowers attached directly to the main axis. - Rachis
The central elongated axis to an inflorescence or a compound leaf. - Ray flower
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). - Receptacle
The enlarged tip of the flowering stem that bears all or most of the flower parts. - Recurved
Curved downward or backwards. - Reflexed
Abruptly bent downward or back. - Replum
Internal membranous partition dividing the fruit of mustards into halves. - Reticulate
In the form of a network as in leaf veins. - Retrorse
Directed backward or downward. - Revolute
Rolled backward from the margin to the lower side. - Rhizomatous
Bearing rhizomes. - Rhizomes
Prostrate stem growing beneath the ground surface, usually rooting at the nodes. - 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. - Rugose
Wrinkled. - Saccate
Shaped like a pouch or bag. - Sagittate
Arrow shaped. - Saline
Consisting of or containing salt. - 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 pistillate flowers. - Scape
A leafless flower stalk. - Scar
A mark left on a stem, branch, or nutlet. - Schist
Medium to coarse-grained metamorphic rock composed of parallel layers which are often waxy or flaky. - Scree
Accumulation of rocky debris lying on a slope or at the base of a hill. - Secund
Oriented on one side of an axis, as in fruits or flowers all being on one side of a stem. - Sedimentary
Rock formed by the deposition and compression of mineral and rock particles. - Seleniferous
Containing or yielding selenium. - Selenium
A non-metallic element that is found with sulfur in various ores; often selectively concentrated by certain legumes. - Sepals
A segment of the calyx. - Septum
Cross-wall or partition. Plural = septa. - Serrate
With sharp teeth pointed forward. - Sessile
Lacking a stalk. - Shale
Fine-grained sedimentary rock, usually composed of clays. - Sheath
The lower part of the leaf that enfolds the stem in grasses, sedges, and rushes. - Shoot
New growth. - Shrub
A woody plant with several equally large stems from the base, usually less than 4.5 m tall. - Sigmoid
Curved in two directions like the letter S. - 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. - Sinuate
Wavy-margined. - Solifluction
Downhill movement of unconsolidated materials that have become saturated with water. - Solitary
Occurring singly, not as part of a group or cluster. - Sorus
A cluster of sporangia (structure containing spores). Plural = sori. - Spathe
Large bract sheathing or enclosing an inflorescence. - Spatulate
Oblong, but narrowed at base. - 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. - Spinescent
Bearing a spine or ending in a spine-like sharp point. - Sporangium
Spore-bearing case. 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. - Spreading
Diverging at nearly a right angle from a structure; nearly prostrate. - Spur
A tubular or sac-shaped extension of a petal or sepal. - Stalk
Main stem of a herbaceous plant. - Stamen
The pollen-producing structures of a flower; the “male” part of a flower. - Staminate
With stamens, but lacking a pistil; “male”. - Staminode
A sterile stamen or any structure lacking an anther but corresponding to a stamen. - Stellate
Star-like or star-shaped; like an asterisk. - Sterile
Non-fertile; structure lacking reproductive parts or abilities. - Stigma
The surface of the pistil on which pollen grains land. - Stipe
Stalk. - Stipitate
Having a stalk (stipe). - 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. - Stoloniferous
Bearing stolons. - Strigillose
Diminutive of strigose. Also, strigulose. - Strigose
Beset with sharp-pointed, straight appressed hairs. - Style
The portion of the pistil between the ovary and the stigma. - Sub
Prefix which refers to under or below. - Subalpine
Region lying below the alpine. - Substrate
Any object or material upon which an organism grows or to which an organism is attached. - Succulent
Fleshy and full of juice. - Subtend
To be situated immediately below, as in bracts beneath a flower. - Sympatric
Applied to species that occupy similar habitats or whose habitats invariably overlap. - Talus
Sloping mass of coarse rock fragments accumulated at the foot of a cliff or slope. - Taproot
The primary root from which secondary (smaller, lateral) roots arise. - Terminal
Located at the tip of a structure. - Ternate
In threes or with three parts. - Ternately compound
Divided into threes, as in a leaf consisting of three leaflets. - Terete
Cylindrical; circular in cross-section. - Tooth
Any small, marginal lobe, usually on the edge of a leaf blade. - Tomentose
With a dense wool-like covering of matted, intertangled hairs of medium length. - Tortuous
Bent or twisted in various directions. - Torulose
Alternately swollen and constricted, a condition often found in the fruit of certain mustards (Brassicaceae). - Translucent
Transmitting light, but causing sufficient diffusion to eliminate perception of distinct images. - Tri
Prefix meaning three or thrice. - Trichome
The specific term for any type of plant hair. - Trifoliate
Having three leaves. - Trifoliolate
Having three leaflets. - Triforked
Divided into three branches, as in hairs that are divided near their tip into three separate branches. - Trigonous
Three-angled, three-sided (usually refers to achenes). - Tubercle
A small expanded structure, such as the base of the style in some sedges, or very large papillae on fruits. - Tuberculate
Having tubercles. - 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. - Twice-pinnate
Two divisions of a leaf blade into leaflets arranged on each side of a common leafstalk. - Twig
The current year’s growth of a 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. - Unilocular
With one locule. - 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. - Villous
Clothed with long, soft hairs, often without special orientation. - Viscid
Sticky; with sticky exudates. - Whorled
Three or more leaves or branches attached at the same level on stem. - Wing
A thin, often dry or leaf-like extension bordering a structure; in some members of the pea family (Fabaceae), the two lateral petals of the flower; or a fruit as in Onagraceae or Cyperaceae. - Woolly
With long, interwoven hairs.
