Aquatic and Wetland Vascular Plants of the Northern Great Plains
62. Cyperaceae, the Sedge Family
1. Bulbostylis Kunth.
1. Bulbostylis capillaris (L.) Clarke
Small tufted annual 0.5-3(4) dm tall; culms usually many, capillary,
usually much surpassing the leaves, longitudinally ribbed, scaberulous. Leaves
mainly basal, the blades short, filiform, to 0.5 mm wide. Inflorescence
of (1)2-5 or more spikelets in a capitate or umbelliform cluster usually less
than 1 cm long, with 1 spikelet sessile and the others pedicellate; involucral
bracts 2-3, filiform, the largest usually surpassing the inflorescence;
spikelets few- to several-flowered, ovoid-oblong, 3-8 mm long; scales
all or nearly all subtending a flower, spirally arranged, dark reddish-brown
with a strong green midrib and membranous margins, ovate, 1.5-2 mm long, blunt-tipped,
puberulent, often deciduous before the achene. Flowers perfect; perianth
none; stamens 2; styles 3-cleft, barely exsert, with a swollen
base that persists on the achene as a tubercle. Achene ivory to tan,
obovoid-trigonous, 0.8-1 mm long, cross-rugulose on the faces; tubercle
minute, mammillate, darker than the achene body and distinct from it. Late Jun--Sep.
Sandy shores, stream banks and alluvial bars; uncommon in c and e NE; (ME and
s Que. to MN and NE s to FL, TX and w to CA; also n Mex. and Cuba).