OregonFlora species comparison

solitary or clustered, trigonous or round.

usually basal;

ligules absent;

blades keeled abaxially; flat; V-, or M-shaped in cross section.

terminal; the spikes either all arising close to one another in head-like clusters or arising separately in cylindrical clusters; some or all clusters usually raised on stalks (rays) (0)2–12(30) cm; if rays absent inflorescence a dense often lobed head of overlapping spikes; secondary rays sometimes present

scales to 76, 2-ranked; each subtending a flower, cylindric to compressed; borne spicately or digitately at ends of rays.

bisexual; in axils of floral scales;

scale bases often decurrent onto rachilla as more or less hyaline wings;

perianth bristles absent;

stamens 1–3;

style base deciduous or persistent;

stigmas 2–3.

biconvex, flattened, or trigonous.

clusters 1–80;

rays usually unequal in length, produced singly from the axils of inflorescence bracts;

involucral bracts 2–12(25), 1–50 cm long, spirally arranged at culm apex, spreading to erect; leaf-like.