achene -- a type of simple dry fruit produced by many species of flowering plants. For example, a rose hip holds a few achenes.

recurved -- Curved backward.

rosette -- usually a dense cluster of leaves at the base of a plant.

bristle -- A straight, stiff hair.

A noxious weed is considered to be harmful to the environment or animals. Often a governing body designates plants as noxious.

disc flowers are those in the center of a sunflower or daisy. Not a ray flower.

serrate -- toothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.

Bracts are modified leaves associated with a flower.

pappus -- Small scales, bristles or hairs at the top of the seed in Asteraceae. For example, dandelion parachutes. Plural: pappi.

basal -- at the base, situated or attached at the base.

spine -- a stiff, sharp structure formed by the modification of a plant organ that contains vascular tissue. A spine can be formed by a latteral branch, a modified leaf or a thorn.

floret -- A small flower, as in the small flowers that make up an Asteraceae flower head.

lanceolate -- Lance-shaped. Long, wider in the middle.

biennial -- a plant which lives for two years, producing a basal rosette of leaves the first year and a full plant, flower, and seed the second year followed by the death of the entire plant at the end of the second year.

genus -- A subdivision of a botanical Family in which all members have a significant number of similar characteristics.

wing -- A maple seed has wings.

leaves alternate along the main stem and are attached singly.

lobe -- Being divided by clefts.