Flora of North America species comparison

solitary or not, trigonous or round, glabrous or scabridulous with extrorse or antrorse (rarely retrorse) prickles.

and leaves with non-Kranz anatomy (C3).

usually basal;

ligules absent;

blades keeled abaxially, flat, V-, or inversely W-shaped in cross section.

terminal, rarely pseudolateral, 1st order subumbellate to capitate, 2d order with spicate or digitately arranged spikelets, rarely a solitary spikelet;

spikelets 1–150; 1st order rays unequal (rarely equal) in length, produced singly from the axils of inflorescence bracts;

involucral bracts 1–22, spirally arranged at culm apex, spreading to erect, leaflike.

spikes;

rachilla persistent, wingless.

scales to 76, distichous, each subtending flower, cylindric to compressed, borne spicately or digitately at ends of rays (occasionally proliferous).

borne in digitate clusters (rarely singly) or in umbellate or glomerulate heads;

floral scales deciduous, 2-keeled or folded (conduplicate).

bisexual [rarely unisexual], in axils of distichous floral scales, bases often decurrent onto rachilla as ± hyaline wings;

perianth absent;

stamens 1–3;

styles linear, 2–3-fid, base deciduous or persistent;

stigmas 2–3.

stamens 1–3;

stigmas 3.

biconvex, flattened, or trigonous.

trigonous, plano-convex, or terete.