Secondary Roads Home Page
taken from Iowa Noxious Weeds, published by
the Iowa Department of Agriculture and Land Stewardship
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Alternate - singly along a stem, one leaf or bud at a node.
Annual- lasting but one growing season.
Axil- point where a leaf or secondary branch joins the stem; the upper angle of the junction of the stem and leaf.
Biennial- plant of two years duration. The first year is often a vegetative form such as a rosette and the second year the plant flowers, forms seeds and dies.
Bract- small leaf-like structure surrounding a flower; belonging to an intlorescence, or sometimes a stem.
Carpel- a simple seed bearing organ, or one member of a compound organ (pistil).
Clasping- blade of the leaf extending beyond and surrounding the stem.
Glandular- supplied with glands or similar structures.
Granular- rough surface with grain-like appearance.
Hoary- grayish-white from fine hairs.
Lanceolate- lance-shaped, tapering at both ends, but broadest at the base and several times longer than wide.
Ligule- an appendage on the inside of a leaf at the junction of sheath and blade.
Linear- long and narrow with nearly parallel edges.
Lobe- a division or segment of a leaf or other plant organ.
Node- joint of a stem that is sometimes enlarged.
Noxious- a plant considered to be extremely destructive or harmful to agriculture and so designated by law.
Oblanceolate- lance-shaped, tapering at both ends, with the broadest part at the tip end and several times longer than wide.
Ovate- egg-shaped with the broadest end near the base.
Panicle- loose, irregularly compound inflorescence with the flowers borne on individual stalks.
Perrennial- a plant that lives more than two years.
Petiole- stem or stalk of a leaf.
Pinnate- compound leaf with the leaflets arranged on each, side of the midrib or vein.'Also used to describe leaves which are lobed or cleft to appear pinnate.
Pistillate- flower with female parts but the male parts are absent.
Plume- (plumose) short hairs attached to filaments of the pappus.
Pubescent- covered with short soft hairs.
Raceme- a simple inflorescence of flowers on stalks of equal length arranged on a single elongated stem.
Rhizome- under ground stem which provide means for the spread of some perennial plants. The term root-stock is used in place of rhizome in many instances.
Rosette- cluster of leaves in circular form without descernible upright stem.
Sheath- lower part of the leaf that encloses the stem on grasses.
Spatulate- enlarged rounded apex with a narrowing and elongated base.
Spike- simple inflorescence with flowers sessile or nearly so upon an elongated stem.
Spikelet- a unit of inflorescence of grasses and sedges, consisting of one or more flowers between two empty glumes.
Staminate- flower has stamens but usually no pistils.
Style- part of a pistil connecting ovary with stigma.
Umbel- simple inflorescence of flowers on stalks which radiate from the same point.
Valve- one of the pieces into which a pod splits.
Whorled- three or more leaves or stems occurring at per single node, often arranged around the stem.
Winged- any membraneous extension or in some instances the extension of the leaf blade beyond that normally expected.
