Plant Glossary
- Achene
A dry one-seeded fruit which does not split. Common in sunflower family and many other flowering plants.
- Acorn
A nut produced by oaks. See nut.
- Acuminate
Drawn out at the apex into a gradually tapering point.
- Acute
Terminating in a sharp or well-defined point.
- Aggregate
A fruit in which separate pistils fuse together when they become a fruit as in blackberries.
- Alien
Same as exotic, can also be noxious or invasive or a weed. Species that did not co-evolve with plants in our area. Generally means plants that arrived here in past 150 years.
- Alternate
Attached singly on a stem; not opposite or whorled.
- Annual
A life cycle in which plant lives through one season only (dies at the end of the growing season).
- Anther
The pollen bearing organ of the flower.
- Appressed
Lying close to, or flat against, such as leaves that lay next to stem.
- Attenuated
Gradual tapering base of a leaf, analogous to acuminate in a leaf tip. Contrasts with cuneate leaf bases which taper abruptly.
- Auricle
Ear or flap like appendage at the base of the leaf sheath in grasses, or at the base of leaf in herbaceous plants as in sagittate or auriculate leaves.
- Awn
A narrow, terminal bristle. Common in grasses.
- Axil
The upper angle between a branch or leaf stalk and the stem from which it grows.
- Basal
Referring to the base of a plant. Basal leaves only occur at base of stem or on ground. A basal rosette for example is a cluster of basal leaves with no stem, as in many biennials.
- Berry
Fleshy fruit of a plant with a pulpy interior, containing many seeds. If fruit has hard nut in center See drupe.
- Bidentate
Two toothed as in the tip of a leaf. If "teeth" are rounded then it is bi-lobed or emarginate. See emarginate.
- Biennial
Plant with a two year life-cycle. Plant usually has a basal rosette the first year, then produces a stem with flowers the second year, then dies. Also called monocarpic.
- Bilabiate
Two-lipped. Often refers to flowers such as mints and figworts (Scophulariaceae). Upper petals are different than the lower petals.
- Bipinnate
Twice-divided in a pinnate structure; generally on ferns and also common in pea family.
- Blade
The flat, expanded part of a leaf, sepal or petal.
- Bog
Open or sparsely treed wetland area poor in mineral mutrients where water is supplied exclusively by precipitation; typically acidic.
- Bract
A specialized leaf with a single flower or inflorescence grown in its axil. Bract can actually be the colorful part of the flower as in the case of dogwood (Cornus spp.) and many paintbrushes (Castilleja spp.).
- Branchlet
A small branch or twig, generally referring to the most recent year's growth.
- Bristle
A stiff hair.
- Bulb
A rounded underground bud or stem with fleshy scales or roots as in onions or garden plants like tulips or daffodils. Similar to corm, but in corm scales are minute and most of structure is the fleshy stem.
- Calyx
Name for all of the sepals as a group. Defined as the outer set of flower parts. Sometimes there is only one group of petal-like structures which may be called tepals.
- Capitate
Head like cluster of flowers.
- Capsule
A dry fruit, generally containing two or more seeds, that splits into sections when mature; also a spore-bearing part of a moss sporophyte.
- Catkin
A thick spike of small male or female flowers without petals, generally wind-pollinated, such as with willows or birches (Salicaceae, Betulaceae).
- Ciliate
Bordered with hairs.
- Clasping
Generally pertaining to leaves which partially surround or wrap around a stem.
- Cleft
Divided to or about the middle into divisions, as a palmately or pinnately cleft leaf. See dissected.
- Compound (leaf)
Consisting of two or more leaflets which partially surround a stem. There should be a scar and a bud at the base of the leaf stem. If there are buds or scars at the base of individual leaflets, then leaves are simple not compound (each is separate).
- Cordate
Heart shaped leaf or base of leaf as in heart leaved arnica (A. cordifolia) or wild ginger (Asarum spp.).
- Corm
Enlarged fleshy base of a stem. Bulb-like but solid (no large scales).
- Corymb
A flat-topped inflorescence, flowers first open at edges, then in center. Flowers are attached at different heights along stalk (rachis) as contrasted with an umbel in which all are attached at one point.
- Crenate
With rounded marginal teeth, as on a leaf margin Cubic cube-shaped.
- Culm
The stem in grasses, includes overlapping leaf sheaths.
- Cuneate
Abruptly tapering base of a leaf. Analagous to acute in leaf tips.
- Cupisidate
With stiff sharp point as in a leaf tip. Similar to mucronate but mucrons are soft, not stiff. For purposes of the plant key in this guide we consider all spine-tipped leaves mucronate.
- Cyme
Inflorescence often with opposite branches in which first flowers mature in center and last ones mature on the furthest branches (opposite of corymbs). As in corymbs flowers are attached at different places along rachis or stem (although they can occur in pairs) but usually not flat topped as in corymbs. If all flower stalks emerge from one point see umbel.
- Decumbant
Prostrate along surface of ground, except for branch tips.
- Decussate
Opposite pairs of leaves that are attached at right angles to the pair below. Common in many herbaceous species.
- Dioecious
Having the male and female reproductive organs on the same plant. Note: when flowers have both sexes they are called "complete" or bisexual not dioecious.
- Disk flowers
Central tubular flowers in the composite or Aster family (the yellow center of a daisy).
- Dissected
Cut into narrow segments (but still attached), as in lobes that nearly reach the midvein in a leaf. Similar to cleft but segments are much narrower, even threadlike when dissected, whereas cleft segments can be wide and rounded.
- Double-toothed
With two different sizes of teeth lining the margins of a leaf, also called doubly-serrate.
- Doubly-serrate
See double-toothed.
- Drupe
Fruit of plums and cherries in the Rose family which are fleshy but with a solid "stone" in the center which is often poisonous.
- Egg-shaped (ovate)
Broader at one end than the other, like the lengthwise cross-section of an egg; attached at the wider end.
- Elliptic
Widest in the middle and tapering equally toward both ends.
- Entire margins
Without teeth, lobes or divisions.
- Erect-spreading
Spreading at an angle of approximately 45 degrees.
- Ericaceous Species
Affiliated with the family Ericaceae (Heath and heather Family).
- Even-pinnate
Pinnately compound but without a terminal leaflet.
- Fascicle
A bundle of branches or leaves as in the pine family.
- Feathermoss
A group of mosses typically with a prostate growth habit and pinnately branched stems.
- Fen
An open or lightly treed wetland habitat, more mineral-rich than a bog because of available groundwater; typically acidic to alkaline.
- Filament
The stem or stalk supporting an anther in a flower.
- Floret
A small flower, one of many making up the head of a composite flower or a spikelet in grasses or sedges Foliose in lichens, a leaf-like growth.
- Follicle
A type of fruit in which sections of the ovary split only on one side. Common in buttercup family and magnolias.
- Frond
The compound leaf of a fern; in mosses, a stem closely and regularly branched in one plane, resembling a fern leaf.
- Glandular-hairy
Containing hair-shaped structures, each with a swollen tip secreteing oils, waxy material or other substances.
- Glaucous
Covered with a waxy or powdery bloom.
- Glume
A bract at the base of a spikelet in the Grass Family.
- Gourd
See melon.
- Head
A dense flower cluster or inflorescence with individual flowers stalkless or on very short stalk. See capitate.
- Hip
A fleshy berry produced by roses (genus Rosa), is only succulent when perfectly fresh, and can make a good tea, rich in vitamins. It generally is quite seedy and dry compared to a true berry.
- Internode
The stem section between two adjacent nodes.
- Invasive
Plant species that can dominate a site, often causing economic harm, especially if it is an alien species. These species often thrive after disturbance such as fire, building construction, over-grazing, or agricultural activities. Some alien species can actually invade and dominate undisturbed sites, overtaking native species. These species are generally the greatest threat for conservation.
- Inversely egg-shaped (obovate)
Egg-shaped, attached at the narrow end.
- Inversely lance-shaped (oblanceolate)
Lance-shaped, attached at the narrow end. See oblanceolate.
- Key
Common term for the fruit of maples and ashes; a dry, winged fruit which does not open at maturity. Also known as a samara.
- Lanceolate (lance-shaped)
Shaped like a lance-head, considerably longer than wide, tapering towards the tip from below the middle; attached at the broad end.
- Lateral
On or from the side of an organ.
- Leaf Scar
The mark left on a stem after a leaf falls off.
- Leaflet
Single part of a compound leaf.
- Legume
Fruit of plants in the pea family. See pod.
- Ligule
In grasses, the thin outgrowth from the inner surface of a leaf where the sheath and blade join.
- Linear
Very narrow and elongated, having parallel sides.
- Lobe
A sub-division of an organ such as a leaf.
- Melon
Large heavy wet fruit with a dry tough skin produced by the cucumber family. Melons tend to have soft fleshy fruit inside, whereas gourds can be quite solid.
- Mesotrophic
Of a moderately rich or productive habitat.
- Monoecious
Having the male and female reproductive organs in separate flowers on the same plant (monoecious or unisexual flowers); or monoecious plants which have only male or female flowers. Flowers which have only one sex are called "incomplete".
- Mucronate
Leaf tip with a soft thread-like spine or mucron. If spine is stiff it is properly called a cupisidate leaf tip.
- Node
A hard, dry, single-seeded fruit which does not open at maturity.
- Nut
A hard, dry, single-seeded fruit which does not open at maturity.
- Nutlet
A small nut. Examples are in borage and mint families which have four small nutlets at the base of the pistil.
- Oblanceolate
Lance-shaped, attached at the narrow end.
- Oblong
Longer than wide having parallel sides.
- Obovate
Egg-shaped, attached at the narrow end.
- Obtuse
A rounded leaf base or tip, generally more broadly rounded than a "round" leaf tip or margin. For purposes of this plant guide rounded and obtuse are both considered rounded.
- Opposite
As leaves appearing in pairs, on the same node, on opposite sides of a stem.
- Orbicular
Circular or spherical.
- Oval
Broadly elliptical.
- Ovate
Broader at one end than the other, like the lengthwise cross-section of an egg; attached at the wider end.
- Palmately Compound
A compound leaf in which the leaflets are arranged as fingers on the palm of your hand. Common example is lupine (Lupinus).
- Palmately Lobed
A simple leaf in which the lobes are arranged as fingers on the palm of your hand. Common example is Norway maple, or vine maple which have seven or more lobes. Rocky mtn maple is more accurately described as tri-lobed.
- Panicle
An elongated, branched inflorescence; a compond raceme.
- Pedicel
An elongated, branched inflorescence; a compond raceme.
- Peregynium
A bract which encloses the seed of a sage plant.
- Perennial
A plant that usually lives more than two years.
- Petal
A division of the inner set of leaf-like flower parts, usually colored.
- Petiole
The stalk which attaches a leaf to the plant.
- Pinnate
Divided, as with a compound leaf, so the segments are arranged on two sides of a middle axis; feather-like in appearance.
- Pinnately Compound
Divided so the leaflets are arranged on two sides of a middle axis; featherlike in appearance.
- Pinnately Lobed
With lobes that extend on two long sides of a leaf as in an oak or a knapweed basal leaf.
- Pinnatified
Cleft in a pinnate manner; appearing pinnately divided; generally of ferns.
- Pistillate
Unisexual flower having only female reproductive organs.
- Pith
The soft, fibrous inner part of a stem or fruit.
- Pod
A dry fruit, consisting of a long, two-valved case encasing the seeds, especially of the pea family. In pea family also called a legume.
- Podetia
The hollow, upright structures of club lichens.
- Pome
An apple-like fruit. Also includes pear, quince and similar fruits in rose family with seeds within membrane embedded in soft fleshy fruit.
- Raceme
An inflorescence where the flowers are borne along the main stem, each with a small stalk or pedicel. If flowers do not have individual stalks see spike.
- Ray
One of the showy, petal-like florets surrounding the flower head in the Aster family.
- Reniform
Kidney-shaped.
- Reticulate
In the form of a network, as the veins of a leaf.
- Rhizome
A horizontal, underground stem system of roots and leafy stems.
- Rosette
A circular leaf cluster, usually at the base of a plant.
- Runner
A very slender, wiry stem, as in the strawberry, that grows along the surface of the soil and propagates by producing roots and shoots at the node at the tip. Also known as a stolon.
- Samara
A dry, winged, one-seeded fruit. Also known as key fruit. Common in elms, ashes and maples.
- Saprophyte
A plant, generally without green colour, which derives its food from dead, organic matter.
- Scale
A thin, reduced leaf or bract; in cones of conifer trees the scales are woody and enclose the seeds.
- Schizocarp
Flower carpels which are fused together when flowering but split into separate fruits when they mature, each of which does not split open (indehiscent). Common example is Geranium.
- Scythe-shaped
Curving prominently to one side; like a scythe.
- Sepal
A part of the outer set of leaf-like flower parts, generally green.
- Sheath
A tube-like which covers another part of a plant, as in the lower portion of the leaf of grasses and sedges which surrounds the stem.
- Silicle
A capsule like fruit in the mustard family which is no more than twice as long as round and splits open when mature. See also silique.
- Silique
A capsule like fruit in the mustard family which is more than twice as long as round and splits open when mature. Is typically long and narrow. See also silicle.
- Simple
A leaf without leaflets, the opposite of a compound leaf. Leaf will generally form a scar at the base (unlike a leaflet).
- Spike
Flowers born along a stem often in dense clusters but without individual pedicels or stalks, as in grasses in the rye or wheatgrass groups, or common mullein.
- Spikelet
The smallest flower cluster in graminoids.
- Spine
A prickly, woody outgrowth from a stem or a leaf; If stiff thick woody outgrowth see a thorn.
- Sporophyte
A spore-bearing structure in a plant, such as the stalk and cones bearing spores in club mosses (Lycopodium spp.).
- Squamule
A small, scale-like growth at the base of club lichens.
- Stalk
The stem of a leaf, flower or moss capsule.
- Staminate
Unisexual (flower) with only male reproductive organs.
- Stipule
A small, leaf-like growth at the base of a leaf stalk.
- Stolon
From the base of a plant, a creeping, horizontal branch or stem which produces new shoots.
- Style
The stalk of the pistil which connects the ovary to the stigma.
- Sub-orbicular
Almost circular or spherical.
- Sub-tripinnate
Almost tripinnate; not quite fully three times divided; usually in ferns.
- Succulent
Fleshy, juicy.
- Tendril
A slim, twisting outgrowth from a stem or leaf; used for climbing or support, like in vines.
- Terminal
At the tip or end of an organ.
- Ternate
Completely three-times divided in a pinnate manner, as in ferns and many members of the buttercup family (Ranunculaceae).
- Thorn
A sharp stiff spine.
- Transverse
Across the breadth of an organ.
- Tri-lobed
Having three lobes on the leaf as in many members of the buttercup family or a rocky mtn maple (Acer glabrum).
- Trifoliolate (3-foliolate)
Having three leaflets such as in box elder (Acer negundo). Also known as ternate.
- Tripinnate
Completely three-times divided in a pinnate manner, as in ferns or some legumes and parsleys.
- Truncate
Leaf with a squared leaf base.
- Tuber
A short, fleshy underground stem or root.
- Umbel
Group of flowers (inflorescence) in which all the stalks emerge from one point forming a umbrella-like head, common in the parsely or carrot family. Often head is flat-topped.
- Urn
Flower with rounded bottom that narrows to opening at tip. Common in heath and heather family. Also known as urceolate.
- Utricle
An inflated achine-like fruit in which the carpel wall loosely holds the single seed. Common in the amaranth family.
- Variety
A taxonomic definition below the rank of species, similar to subspecies or cultivar.
- Venation
The arrangement of veins on a leaf.
- Weed
"a plant for which a use has not yet been found" or "a plant in the wrong place" or an unwanted plant. Ecologists consider a weed a plant that thrives in disturbed habitats, with prodigious seed and fruit production and usually is short-lived. Noxious weeds are plants that do sufficient economic harm in a given state that they are regulated. So a plant that is noxious in Montana is not necessarily noxious in Maryland, or even Idaho. see also alien.
- Whorl
A collection of three or more similar organs projecting from a node. Commonly applied to leaves such as bedstraw which has 4 to 6 or more leaves at each node of the stem (Galium spp. ) and lilies (Lilium spp.).
Northern Rockies Natural History Guide
