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.
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.