Bouteloua barbata var. rothrockii

(Vasey) Gould
Common names: Rothrock's grama
Synonyms: Bouteloua rothrockii
Treatment appears in FNA Volume 25. Treatment on page 265.

Plants short-lived perennials; not stoloniferous. Culms 25-60 (75) cm, stiffly erect or slightly geniculate-spreading basally; ligules 0.1-0.5 mm; blades 6-10 cm long, 1-4 mm wide. Panicles (3.5) 5-25 cm, with 3-8 branches; branches 15-30 mm, scabrous, with 35-50 (55) spikelets. 2n = 40.

Discussion

Bouteloua barbata var. rothrockii grows on dry slopes and sandy flats, mostly at 750-1700 m. It grows throughout the southwestern United States and Mexico, sometimes covering large areas. It used to be the most important forage grass in southern Arizona and neighboring regions.

Bouteloua barbata var. rothrockii resembles B. parryi var. parryi, but can be easily distinguished from that taxon by the lack of papillose-based hairs on the keels of its upper glumes.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

1 +  and 3 +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
puberulent +  and glabrous +
J.K. Wipff +
(Vasey) Gould +
1 (?) +  and 3 (?) +
well-developed +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
pubescent +  and glabrous +
usually linear +  and lanceolate occasionally ovate +
1mm;4mm +
subdigitate +  and digitate +
75 cm750 mm <br />0.75 m <br /> (?) +
straight +  and arcuate +
persistent +
scabridulous +
spikelike +
not woody +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Rothrock's grama +
geniculate-spreading +  and erect +
25 cm250 mm <br />0.25 m <br /> (60 cm600 mm <br />0.6 m <br />) +
not woody +
Md. +, Kans. +, Okla. +, Colo. +, N.Mex. +, Tex. +, Utah +, Calif. +, Mont. +, Ariz. +, Oreg. +  and Nev. +
not waisted +
capillary +
pistillate +  and staminate +
4-lobed +  and trilobed +
sometimes longer +
rudimentary +
2 +  and 1 +
flabellate +  and 2-lobed +
reduced +
1.5mm +  and 4mm +
shorter or longer +
subtending +
both +  and 1 +
scabridulous +
acuminate +  and acute +
unequal +
not papillose-based +  and papillose-based +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
cauline +  and basal +
5-veined +, 7-13-veined +  and 1-3-veined +
sometimes longer +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
membranous +
rounded +
membranous +
inconspicuous +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
concealed +  and prominent +
2 +  and 1 +
3.5 cm35 mm <br />0.035 m <br /> (?) +
5 cm50 mm <br />0.05 m <br /> (25 cm250 mm <br />0.25 m <br />) +
dry +  and fleshy +
spikelike +
elongate +
flabellate +
sessile +  and subsessile +
well-developed +
35 +  and 50 +
pectinate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 (?) +  and 3 (?) +
compound +  and simple +
2 (?) +  and 3 (?) +
Bouteloua rothrockii +
Bouteloua barbata var. rothrockii +
Bouteloua barbata +
variety +
membranous +
strigose +, scabrous +  and glabrous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
7 +  and 13 +
extended +
perennial +  and short-lived +
short-lived +  and annual +
aquatic +  and terrestrial +