1. Rhynchospora capillacea Torr. (beaked rush)

Pl. 78 a–c; Map 299

Plants forming dense clumps, with slender, branched rhizomes. Aerial stems 10–40 cm long, very slender. Leaves basal and usually 1–2 on the lower portions of the aerial stems, the leaf blades 4–40 cm long, 0.2–0.4 mm wide, hairlike, the margins inrolled. Inflorescences of 1–2(–3) clusters of spikelets, less commonly with individual spikelets. Spikelets 5–7 mm long, lanceolate to narrowly elliptic in outline, pointed at the tip, with 1–5 of the florets fertile. Spikelet scales 3–4 mm long, elliptic to ovate with the midrib minutely extended past the pointed tip, reddish brown to dark brown. Perianth bristles 6, longer than the fruits, with downwardly pointing barbs. Fruits with the tubercle 0.8–1.6 mm long, narrowly triangular-attenuate, the main body 1.7–2.1 mm long, narrowly elliptic to narrowly obovate in outline, the surface patterned with fine, wavy, horizontal lines, sometimes appearing finely wrinkled, uniformly brown at maturity. 2n=26. June–September.

Scattered in the Ozark and Ozark Border Divisions, mostly in the eastern half of the state (northeastern U.S. and adjacent Canada west to South Dakota and Missouri). Fens and calcareous seeps of rocky ledges of bluffs and stream banks.

This plant is a good indicator of calcareous seeps and fens. The slender stems and leaves make it easily overlooked in the field.