2. Rhynchospora capitellata (Michx.) Vahl (false bog rush)

Pl. 79 a, b; Map 300

R. glomerata (L.) Vahl var. minor Britton

Plants tufted. Aerial stems 30–80 cm long. Leaves basal and progressively reduced on the aerial stems, the leaf blades 5–70 cm long, 1.5–3.5 mm wide, flat. Inflorescences of 2 to several clusters of spikelets. Spikelets 3.5–5.5 mm long, ovate to elliptic in outline, pointed at the tip, with 1–2(–5) of the florets fertile. Spikelet scales 2.5–3.5 mm long, ovate to elliptic with the tip pointed, brown to dark brown. Perianth bristles 6, mostly longer than the fruits, with downwardly pointing barbs. Fruits with the tubercle 0.8–1.6 mm long, narrowly triangular-attenuate, the main body 1.8–2.8 mm long, obovate in outline, flattened, the surface smooth, shiny, yellowish brown to brown with conspicuously pale, narrow, raised margins. May–October.

Scattered, mostly in the southern third of the state (eastern U.S. and adjacent Canada west to Texas; disjunct in California and Oregon). Rocky or sandy banks of streams and spring branches, moist depressions of sandstone and igneous glades, and fens; less commonly in mesic swales of upland prairies, sinkhole ponds, and moist, open, disturbed areas.