OregonFlora species comparison

5–40(95) cm.

solitary or clustered, trigonous or round.

3–20(30) cm × 1.5– 3 mm.

usually basal;

ligules absent;

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

clusters densely head-like; ovoid to hemispheric, 7–16(20) mm diameter;

rays (0)1–2, 0.3–4.5 cm;

inflorescence bracts 2–3; horizontal to reflexed downward.

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

(3)5–25(60), linear to oblong-linear, compressed; (3)5–9 × 1.8–2.3 mm; floral scales 4–18, closely imbricate; ovate to orbiculate, 1.5–2.1 × 1.4–2.2 mm; chestnut brown; black, or brown, medially green or greenish brown, laterally ribless, medially 2(3)-ribbed, distinctly 2-keeled basally;

apex obtuse.

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

anthers 0.6–0.8 mm;

styles 0.4–0.6 mm;

stigmas 0.7–2.1 mm.

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.

ellipsoid, 1.2–1.4 × 0.6–0.8 mm, with network of ridges forming isodiametric or square cells.

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.