Aerial: Occurring above ground or water.
Alternate: Leaf attachments are singular at nodes, and leaves alternate direction, to a greater or lesser degree, along the stem.
Annual: An annual plant is a plant that usually germinates flowers and dies in one year.
Auricles: Earlike structures found at the junction of the blade and sheath; extensions of the leaf blade around the stem.
Awn: A narrow, hair-like bristle
Axil: The position between the stem and a leaf.
Axillary: Positioned in or arising in an axil.
Basal rosette: Cluster of leaves radiating form the base of the stem at ground level.
Bract: A reduces leaf or leaf-like structure at the base of a flower or flower cluster.
Bristle: A short, stiff hair or hair-like structure.
Collar: The area on the outside of a grass leaf at the junction of the blade and the sheath.
Cotyledon: A primary leaf of the embryo; a seed leaf.
Creeping roots: Thickened roots that store carbohydrates, spread vertically and horizontally in the soil, and contain adventitious buds that give rise to new plants.
Disk flower: The central flowers of a flower head in the Asteraceae (aster family).
Disseminate: To disperse throughout.
Glume: One of the paired bracts at the base of a grass spikelet.
Herbaceous: A non-woody plant with stems and leaves that die back to the ground in the winter.
Ligule: A membraneous or hairy structure arising on the inside of the leaf at the junction of the blade and sheath.
Node: The position on the stem where leaves or branches originate.
Ocrea: A membranous, papery sheath around the stem at the nodes as in members of the Polygonaceae (smartweed family).
Palmate: Lobed, veined or divided from a common point, like the fingers of a hand.
Panicle: A flower cluster with a main axis and subdivided branches that is often pyramid-shaped.
Pappus: The feathery or hairy portion of a seed used to facilitate wind dispersal.
Petiole: A leaf stalk.
Pinnate: The word used to describe a compound leaf with leaflets arranged on opposite sides of an elongated axis.
Prickle: A small, sharp outgrowth of the stem surface.
Ray flower: The strap-like outer flowers of a flower head in the Asteraceae (aster family).
Rhizome: Belowground modified stem that gives rise to new plants.
Samara: A dry, winged fruit.
Sepal: The outermost part of a flower; typically green and leaf-like.
Spikelet: The individual flower clusters of grasses and sedges, consisting of one to many flowers subtended by two bracts (glumes).
Spine: A stiff, slender, sharp-pointed structure arising from below the epidermis.
Stipules: A pair of leaf-like structures found at the base of a leaf.
Stolon: Aboveground modified stem that gives rise to new plants.
Summer Annual: Summer annuals sprout, flower and die within the same spring/summer/fall.
Terminal: The tip or end of a stem or leaf.
Thorn: A stiff, woody, modified stem with a sharp point.
Tiller: A shoot, especially one that sprouts from the base of a grass.
Trifoliolate: The word used to describe a compound leaf consisting of three leaflets.
Tuber: The thickened portion of a rhizome bearing nodes and buds; underground stem modified for food storage.
Whorl: Arrangement of three or more parts arising from a common point, as in a leaf arrangement with three or more leaves per node.