Glossary - Plants Terminology

  • A

  • Acicular: leaf narrow, long and pointed; as pine leaves.
  • Alternate: attached singly on a stem; not opposite or whorled (see pictorial glossary).
  • Awn: a narrow, terminal bristle.
  • Axil: the upper angle between a branch or leaf stalk and the stem from which it grows.
  • B

  • Basal: referring to the base of a plant.
  • Berry: fleshy fruit of a plant with a pulpy interior, containing seeds.
  • Bipinnate: twice-divided in a pinnate structure; generally on ferns (see pictorial glossary).
  • 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 growin in its axil.
  • Branchlet: a small branch or twig, generally referring to the most recent year's growth.
  • Bristle: a stiff hair.
  • C

  • 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.
  • Ciliate: bordered with hairs.
  • Clasping: generally pertaining to leaves which partially surround a stem.
  • Compound (leaf): consisting of two or more leaves which partially surround a stem.
  • Crenate: leaf margin with round teeth.
  • Cubic: cube-shaped.
  • D

  • Dentate: leaf margins with continuous teeth which point outwards.
  • Denticulate: margins with small pointed teeth directed outward, perpendicular to the midrib, diminutive of dentate.
  • Diamond-shaped (rhomboid): a leaf in the form of a rhomb: a quadrilateral figure having only its opposite sides and angles equal.
  • Dioecious: having the male and female reproductive organs on the same plant.
  • Doubly-serrate: with two different sizes of teeth lining the margins of coarse teeth (see pictorial glossary).
  • E

  • Egg-shaped (ovate): broader at one end than the other, like the lengthwise cross-section of an egg; attached at the wider end (see pictorial glossary).
  • Elliptical: widest in the middle and tapering equally toward both ends (see pictorial glossary).
  • Entire: margins without teeth, lobes or divisions (see pictorial glossary).
  • Erect-spreading: spreading at an angle of approximately 45 degrees.
  • Ericaceous Species : affiliated with the family Ericaceae (Heath Family).
  • F

  • Fan-shaped (flabellate): leaf shaped like a fan. Like a gingko.
  • Fascicle: a bundle of branches or leaves.
  • 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 due because of available groundwater; typically acidic to alkaline.
  • Floret: a small flower, one of many making up the head of a composite flower.
  • Foliose: in lichens, a leaf-like growth.
  • Frond: the compound leaf of a fern; in mosses, a stem closely and regularly branched in one plane, resembling a fern leaf.
  • G

  • 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.
  • H

  • Head: a dense flower cluster or inflorescence with individual flowers stalkless or on very short stalk.
  • Heart-Shaped (cordate): leaves are often triangular, sometimes cordate or sagittate at the base.
  • I

  • Internode: the stem section between two adjacent nodes.
  • Inversely Egg-shaped (obovate): egg-shaped, attached at the narrow end (see pictorial glossary).
  • Inversely Heart-shaped (obcordate): in the shape of a heart with the pointed end at the base.
  • Inversely Lance-shaped (oblanceolate): lance-shaped, attached at the narrow end (see pictorial glossary).
  • K

  • 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.
  • Kidney-Shaped (reniform): resembling the shape of kidney.
  • L

  • Lance-shaped (lanceolate): shaped like a lance-head, considerably longer than wide, tapering towards the tip from below the middle; attached at the broad end (see pictorial glossary).
  • 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.
  • 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 (see pictorial glossary).
  • Lobate: lobes on entire margin. Like oak.
  • Lobe: a sub-division of an organ such as a leaf (see pictorial glossary).
  • M

  • Mesotrophic: of a moderately rich or productive habitat.
  • Monoecious: having the male and female reproductive organs in separate flowers on the same plant.
  • N

  • Node: the point on a stem where a leaf, bud or branch arises; in grasses, a noticable swelling or joint occurs at each node.
  • Nut: a hard, dry, single-seeded fruit which does not open at maturity.
  • Nutlet: a small nut.
  • O

  • Oblong: longer than wide having parallel sides (see pictorial glossary).
  • Opposite: as leaves appearing in pairs, on the same node, on opposite sides of a stem (see pictorial glossary).
  • Orbicular: circular or spherical.
  • Oval: broadly elliptical (see pictorial glossary).
  • P

  • Palmate: of a leaf, divided into several leaflets which arise at the same point. Usually 5-7.
  • Panicle: an elongated, branched inflorescence; a compond raceme.
  • Perennial: a plant that usually lives more than two years.
  • Peregynium: a bract which encloses the seed of a sage plant.
  • Petal: a division of the inner set of leaf-like flower parts, usually coloured.
  • 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; featherlike in appearance (see pictorial glossary).
  • Pinnate-Pinnatifid: the pinnae themselves are deeply divided, but not fully divided out to the tip to form separated pinnules.
  • Pinnatifid: cleft in a pinnate manner; appearing pinnately divided; generally of ferns (see pictorial glossary).
  • 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.
  • Podetia: the hollow, upright structures of club lichens..
  • Polygamous: having having male, female and hermaphrodite flowers on the same plant or on separate plants of the same species.
  • R

  • Raceme: an inflorescence where the flowers are borne along the main stem.
  • Ray: one of the showy, petal-like florets surrounding the flower head in the Aster Family.
  • 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.
  • Runcinate: having tooth-like projections pointing away from the apex.
  • 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.
  • S

  • Sagittate: shaped like an arrowhead, with one point at one end, and two points at the other
  • Samara: a dry, winged, one-seeded fruit. Also known as key fruit.
  • 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.
  • Scythe-shaped: Curving prominently to one side; like a scythe.
  • Sepal: a part of the outer set of leaf-like flower partsthe, generally green.
  • Serrate: margins with pointed teeth directed forward, towards the apex of the leaf.
  • Serrulate: margins with small pointed teeth directed forward, towards the apex of the leaf, diminutive of serrate.
  • 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.
  • Sinuate: strongly wavy margins with shallowly rounded divisions within the same plane of the blade.
  • Spatulate: spatula-shaped leaf; having a broad rounded apex and narrow base.
  • Spearhead-shaped (hastate): having a narrow triangular shape like that of a spearhead.
  • Spikelet: the smallest flower cluster in graminoids.
  • Spine: a prickly, woody outgrowth from a stem; a thorn.
  • Spiny: margins which has spines pointing outwards.
  • Sporophyte: a spore-bearing plant.
  • 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 leafstalk.
  • 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 (see pictorial glossary).
  • Succulent: fleshy, juicy.
  • T

  • 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.
  • Thorn: a sharp spine.
  • Transverse: across the breadth of an organ.
  • Triangular: leaf shaped almost identically to triangle.
  • Trifoliolate (3-foliolate): having three leaflets (see pictorial glossary).
  • Tripinnate: completely three-times divided in a pinnate manner, as in ferns. (see pictorial glossary).
  • Tuber: a short, fleshy underground stem or root.
  • U

  • Undulate: margin which are widely wavy.
  • V

  • Variety: a taxonomic definition below the rank of species.
  • Venation: the arrangement of veins on a leaf.
  • W

  • Whorl: a collection of three or more similar organs projecting from a node (see pictorial glossary).