Setaria adhaerans
Setaria macrostachya
bur bristlegrass, tropical barbed bristlegrass
large-spike bristlegrass, plains bristlegrass
25-60 cm.
60-120 cm, rarely branched distally, scabrous below the nodes and panicles.
glabrous throughout;
ligules 1-2 mm, of hairs, white;
blades usually less than 10 cm long, 5-10 mm wide, flat, broad basally, abaxial surfaces conspicuously strigose with papillose-based hairs, tapering abruptly at the apices;
bristles solitary, about 5 mm, retrorsely scabrous.
keeled, glabrous, usually with a few white hairs at the throat;
ligules 2-4 mm, densely ciliate;
blades 15-20 cm long, 7-15 mm wide, flat, adaxial surface scabrous.
2-6 cm, verticillate, green to purple;
rachises retrorsely rough hispid.
10-30 cm long, 1-2 cm wide, uniformly thick from the base to the apex, dense, rarely lobed basally;
rachises scabrous and loosely pilose;
bristles usually solitary, 10-20 mm, soft, antrorsely scabrous.
1.5-2.2 mm.
2-2.3 mm, subspherical.
about 1/2 as long as the spikelets, obtuse, 1(3)-veined;
upper glumes nearly as long as the spikelets, 5-7-veined;
lower lemmas equaling to slightly exceeding the upper lemmas;
lower paleas less than 1/2 as long as the spikelets, scalelike;
upper lemmas finely and transversely rugose;
upper paleas similar to the upper lemmas.
1/3 – 1/2 as long as the spikelets, 3-5-veined;
upper glumes about 3/4 as long as the spikelets, 5-7-veined;
lower lemmas equaling the upper lemmas, 5-veined;
lower paleas nearly equaling the upper paleas in length and width;
upper lemmas transversely rugose;
upper paleas convex, ovate.
= 18.
= 54.
Setaria adhaerans
Setaria macrostachya
Setaria adhaerans grows in subtropical regions throughout the world. In North America, it is known from the southern United States, northeastern Mexico, Guatemala, Cuba, and the Bahamas. The Californian record may represent a recent introduction.
Setaria adhaerans resembles the temperate S. verticillata, but differs in having shorter panicles, shorter spikelets, glabrous sheath margins, and papillose-based strigose hairs on the blades.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Setaria macrostachya is abundant in the desert grass-lands of the southwestern United States, particularly in southern Arizon and Texas. It extends south through the highlands of central Mexico. It also grows in the West Indies, but is not common there. It is a valuable forage grass in the Flora region.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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CalFlora
USDA Plants Database
