Bothriochloa alta
Bothriochloa wrightii
tall beardgrass, tall bluestem
Wright's beardgrass, Wright's bluestem
1.3-2.5 m tall, 2-4 mm wide, stiffly erect, not or only sparingly branched;
nodes hirsute, hairs 2-6 mm, stiff, spreading, tan;
internodes glaucous below the nodes.
to 70 cm, erect, sparingly branched;
nodes glabrous or hirsute, hairs about 1 mm.
cauline;
ligules 1-3 mm;
blades 20-30 cm long, 4-10 mm wide, glabrous or sparsely pilose near the base.
cauline, glaucous;
ligules 1-2 mm;
blades 15-25 cm long, 3-7 mm wide, glabrous.
14-25 cm long on the larger shoots, 3-6 cm wide when pressed, oblong, dense;
rachises 10-20 cm, with numerous branches, rachises and branches kinked and wavy at the base from being compressed in the sheath;
branches 2-8 cm, much shorter than the rachises, erect to appressed, with multiple rames;
rame internodes villous on the margins, with 5-8 mm distal hairs.
5-6 cm, oblong to fan-shaped;
rachises 1-3 cm, with 4-5 branches;
branches 4-6 cm, lacking axillary pulvini, with 1 rame;
rame internodes with stiff, 1-3 mm marginal hairs.
spikelets 4.5-6 mm, ovate;
lower glumes shortly pilose, with or without a dorsal pit;
awns 18-22 mm;
anthers about 1 mm, often remaining in the floret, light brown.
spikelets 5.5-7 mm, lanceolate-elliptic;
lower glumes glabrous, usually without a dorsal pit;
awns 10-15 mm, twisted, once-geniculate;
anthers about 3 mm.
spikelets 3.8-4.4 mm.
spikelets staminate, subequal to the sessile spikelets.
= 120.
= 120.
Bothriochloa alta
Bothriochloa wrightii
Bothriochloa alta grows along roads, drainage ways, and gravelly slopes in the desert grasslands of the south-western United States, at 600-1200 m, and extends south to Bolivia and Argentina. It is not a common species in the Flora region. It often grows with and is mistaken for B. barbinodis, but differs from that species in having longer culms, panicles, and nodal hairs, and 2n = 120. Plants in the southwestern United States have larger spikelets and more hairy panicles than those of central Mexico, where the species was originally described.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Bothriochloa wrightii grows in rocky grasslands and shrubby slopes of the pine-oak woodlands of southern Arizona, New Mexico, Texas, and northern Mexico, at 1200-1800 m. It was last collected in the United States in 1930. It differs from B. barbinodis in its glaucous foliage, short, fan-shaped panicles, and large, pedicellate spikelets.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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USDA Plants Database
