Missoula County Weed District & Extension

Plant Definitions

Adventitious: A structure arising from an unusual place, such as roots growing from leaves or stems

Alternate: Situated singly at each node

Annual: Living for only one year

Biennial: Living for two years usually flowering and producing fruit the second year

Bract: a reduced or specialized leaf associated with, but not part of, a flower or flower cluster

Bud: a structure from which growth (stem, leaf, or flower) arises

Compound: composed of many individual parts

Deciduous: falling after the completion of its function, often at the approach of a dormant season. (eg. Deciduous trees lose their leaves in the fall)

Entire: without indentation or division

Evergreen: bearing foliage throughout the year

Forb: a broad-leaved, non-woody plant that dies back to the ground after each growing season

Glabrous: without hairs, smooth

Herb: a plant without woody above-ground parts, the stems die back to the ground each year

Herbaceous: herb-like

Involucral bracts: a set of bracts beneath an inflorescence

Lateral: on the side of

Leaf: the main photosynthetic organ on a plant

Leaflets: the divisions of a compound leaf

Midrib: the central leaf vein

Node: a place where a leaf or branch is attached

Opposite: situated across from each other

Palmate compound: leaves divided into three or more lobes or leaflets diverging from a common point, like fingers on a hand

Perennial: growing for three or more years, usually flowering and producing fruit each year

Rhizomatous: an underground, often lengthened stem; distinguished from a root by the presence of nodes and buds or scale-like leaves; often used by plant to spread vegetatively.

Root: the usually underground organ that lacks buds or leaves or nodes; absorbs water and mineral salts; usually it anchors the plant to the ground

Rosette: a cluster of organs (usually leaves) arranged in a circle or a disk, often at the base of the plant

Simple: not divided or sub-divided

Shoot: A stem or branch and its leaves, especially when young

Stolon: a horizontally spreading stem or runner on the ground usually rooting at nodes or tips

Taproot: a primary descending root (looks like a carrot)

Umbelliform: in the shape of an umbel; much like the shape of a reversed umbrella