Bothriochloa laguroides |
Bothriochloa wrightii |
|
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silver beardgrass, silver bluestem |
Wright's beardgrass, Wright's bluestem |
|
Culms | 35-115(130) cm tall, usually less than 2 mm thick, erect or geniculate at the base, branched at maturity; nodes shortly hirsute, pilose with erect hairs, or glabrous. |
to 70 cm, erect, sparingly branched; nodes glabrous or hirsute, hairs about 1 mm. |
Leaves | usually basal (sometimes cauline on robust plants), usually glaucous; ligules 1-3 mm; blades 5-25 cm long, 2-7 mm wide, flat to folded, mostly glabrous. |
cauline, glaucous; ligules 1-2 mm; blades 15-25 cm long, 3-7 mm wide, glabrous. |
Panicles | 4-12(14) cm, narrowly oblong or lanceolate, silvery-white or light tan; rachises 4-8 cm, with more than 10 branches; branches 1-5.5 cm, erect-appressed, rarely with axillary pulvini, lower branches shorter than the rachises, usually with more than 1 rame; rame internodes with a groove wider than the margins, margins copiously hairy, hairs 3-9 mm, at least somewhat obscuring the spikelets. |
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. |
Sessile | spikelets 2.5-4.5 mm, ovate, somewhat glaucous, apices blunt; lower glumes glabrous or hirtellous, rarely with a dorsal pit; awns 8-16 mm; anthers 0.6-1.4 mm. |
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. |
Pedicellate | spikelets 1.5-2.5(3.5) mm, shorter than the sessile spikelets, sterile. |
spikelets staminate, subequal to the sessile spikelets. |
2n | = 60. |
= 120. |
Bothriochloa laguroides |
Bothriochloa wrightii |
|
Distribution |
AL; AR; AZ; CA; CO; FL; GA; IL; IN; KS; KY; LA; MO; MS; NE; NM; NV; OH; OK; SC; TN; TX; UT; HI
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AZ; NM; TX |
Discussion | Bothriochloa laguroides grows in well-drained soils of grasslands, prairies, roadsides, river bottoms, and woodlands, often on limestone, usually at 20-2100 m. Plants from the United States and northern Mexico belong to B. laguroides subsp. torreyana (Steud.) Allred & Gould, which differs from B. laguroides (DC.) Herter subsp. laguroides in its glabrous, or almost glabrous, nodes, long internode hairs, and pilose throat region. Occasional plants are found with spreading branches and axillary pulvini; they do not merit formal recognition. Bothriochloa laguroides subsp. torreyana is used in landscaping. It does well on rocky slopes and sandy banks. Bothriochloa laguroides has been confused with B. saccharoides (Sw.) Rydb., a more southern species that differs from B. laguroides in having pilose leaves, a narrow central groove in the internodes and pedicels, and panicle branches with axillary pulvini. (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.) |
Source | FNA vol. 25, p. 640. | FNA vol. 25, p. 640. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Andropogoneae > Bothriochloa | Poaceae > subfam. Panicoideae > tribe Andropogoneae > Bothriochloa |
Sibling taxa | ||
Name authority | (DC.) Herter | (Hack.) Henrard |
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