keys to the vascular plants of east texas - Botanical Research ...

634 CYPERACEAE/RHYNCHOSPORA
Rhynchospora miliacea (Lam.) A. Gray, (pertaining to millet), MILLET BEAK SEDGE. Rhizomatous
perennial to 1.5 m tall; inflorescence branches nearly at right angles to the main axis, the inflorescence
appearing very open, each spikelet or small cluster of spikelets on a slender stalk;
spikelets 2.5–3.5 mm long; achenes 1.1–1.2 mm long, broadly obovoid, tumidly biconvex; tubercle
0.2–0.3(–0.4) mm long, the margins with minute bristles. Seepage slopes in pine woodlands,
other low wooded areas; Jasper, Tyler (BRIT), and Walker (Turner et al. 2003) cos. in se part of
East TX; se U.S. from VA s to FL w to TX. Sep–Oct. [Schoenus miliaceus Lam.] This species was
first reported for TX in 1982 (Nixon & Ward 1982). According to Kral (2002c), “The ultimate
branches in Rhynchospora miliacea typically terminate in only one or two spikelets, the scales
of which fall quickly, and the exposed fruits look like short miniature strings of beads.” (TOES
1993: IV) �
Rhynchospora mixta Britton, (mixed), MINGLED BEAK SEDGE. Rhizomatous perennial to 100 cm
tall, the slender rhizomes often to 10 cm or more long; inflorescences with spikelet clusters
mostly diffuse; spikelets usually 3–4 mm long; achenes 1.2–1.5 mm long, ellipsoid to narrowly
obovoid, lenticular; tubercle 0.5–0.6(–0.8) mm long, the margins with minute bristles. Wet
woods; Hardin, Harris, Jasper, Newton, Orange, Polk, San Jacinto (BRIT), Montgomery,
Nacogdoches, and Walker (Turner et al. 2003) cos. in the se part of East TX; se U.S. from NC s to
FL w to TX. May–Sep. [R. prolifera Small] This species can be confused with R. caduca (see key
to species).
Rhynchospora nitens (Vahl) A. Gray, (shining), SHORT-BEAK BALD-RUSH, SHORT-BEAK BEAK SEDGE,
BALD-RUSH. Glabrous annual 15–80(–100) cm tall; spikelets 4–6(–9) mm long, with numerous
scales; perianth bristles absent; achenes 0.7–1 mm long, ca. as broad as long, nearly orbicular,
tumidly lenticular; tubercle much wider than long. Wet open areas, sandy or sandy peat soils;
Milam (BRCH), Hardin, and Jefferson (Turner et al. 2003) cos.; also Gulf Prairies and Marshes;
scattered in the e U.S. w to MI and TX. Jul–Aug. Previously segregated into the genus Psilocarya
[as P. nitens (Vahl) A.W. Wood or P. portoricensis Britton]
Rhynchospora nivea Boeck., (snowy, white), SNOWY WHITE-TOP SEDGE, SHOWY WHITE-TOP. Tufted
glabrous perennial 7–30(–40) cm tall; inflorescence a small head of ca. 3–11 spikelets; longer
bracts (0.7–)1.7–3.7(–6) cm long; white zone only at the very base of bract; spikelets 3.5–7(–8)
mm long, with white scales; achenes 0.8–1 mm long, broadly obovoid, tumidly lenticular. Creek
beds on limestone, wet areas, basic soils; Bell, Travis (BRIT), Hill (White et al. 1998b), Bexar,
Comal, Dallas, Gonzales, Hays, Walker, and Williamson (Turner et al. 2003) cos., also collected
along Turtle Creek, Dallas (Austin Chalk) in 1881 or 1882 by Reverchon, noted as “very rare”
and not found there since (Thomas 1984; Mahler 1988); also Cross Timbers and Prairies and
Edwards Plateau; OK and TX. Apr–Oct. Previously separated into the genus Dichromena [as D.
nivea (Boeck.) Boeck. ex. Britton and D. reverchonii S.H. Wright]. Bees and flies have been observed
visiting and presumably pollinating this species (Thomas 1984).
Rhynchospora oligantha A. Gray, (few-flowered), FEW-FLOWER BEAK-RUSH, FEATHER-BRISTLE
BEAK SEDGE. Densely tufted perennial to 40 cm tall; inflorescences very sparse, with spikelets
borne individually on pedicels or in well-spaced clusters of 2–5; spikelets usually (4–)4.5–6(–8)
mm long; perianth bristles plumose at least near base; achenes (1.7–)2.2–2.5(–2.6) mm long,
ellipsoid-obovoid, tumidly lenticular, with a distinctive neck at apex, narrowed and then flaring;
tubercle 0.4–0.7 mm long. Swamps, bogs, pine savannahs; scattered in the Pineywoods and
Post Oak Savannah; mainly se U.S. from N.J. s to FL w to TX. May–Aug.
Rhynchospora perplexa Britton, (puzzling, tangled), PINELAND BEAK SEDGE. Tufted perennial to
110 cm tall; inflorescences variable, with spikelet clusters often widely spaced; spikelets 2–3
mm long; perianth bristles 0–3(–6), absent or rudimentary; achenes 1–1.3 mm long, orbicular to
broadly obovoid, strongly flattened; tubercles 0.2–0.3 mm long. Lake and pond margins, depressions,
seeps, sandy or peaty soils; s part of East TX n to Leon Co. (Turner et al. 2003); also