Bouteloua radicosa

(E. Fourn.) Griffiths
Common names: Purple grama
Treatment appears in FNA Volume 25. Treatment on page 259.

Plants perennial; cespitose, with a dense, hard, knotty base, rhizomatous, rhizomes 2-3 mm thick, with pale cataphylls; internodes 4-5 mm. Culms (40) 60-80 cm, erect, straight, unbranched. Sheaths. strongly striate; ligules 0.5-1 mm, of hairs; blades mostly basal, short and firm, 2-3 mm wide, bases with papillose-based hairs on the margins. Panicles 10-15 cm, usually with 7-12 branches; branches (15) 20-30 mm, deciduous, with 8-11 spikelets, apices entire; disarticulation at the base of the branches. Spikelets appressed, all alike, with 2 florets, lowest floret bisexual, upper florets pistillate, bisexual, or staminate. Glumes acuminate, glabrous; lower glumes about 4 mm; upper glumes 5-6 mm; lowest lemmas 7-8 mm, smooth, often shortly trilobed, 3-awned, awns extending from the lobes, central awns 2-3 mm, not flanked by membranous lobes, lateral awns about 1 mm; lower paleas 6-7 mm, unawned, sometimes mucronate; upper lemmas 9-10 mm, central awns 6-8 mm, lateral awns 5-6 mm; upper paleas similar to the lower paleas. Caryopses 4-5 mm long, 0.75-1 mm wide. 2n = 60.

Discussion

Bouteloua radicosa grows on dry, rocky slopes at 1000-3000 m, from Arizona and southern New Mexico to southern Mexico. It has also become established in Maine, growing in disturbed habtiats, but is not common there.

Bouteloua radicosa frequently grows with B. repens at lower elevations, but extends higher than that species. Like B. repens, B. radicosa exhibits great variation in spikelet and inflorescence characters. Gould (1979) suggested that some of the variation in B. radicosa was due to hybridization with B. repens in the Flora area and B. williamsii Swallen in southern Mexico.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Bouteloua radicosa"
1 +  and 3 +
J.K. Wipff +
(E. Fourn.) Griffiths +
1 (?) +  and 3 (?) +
well-developed +
keeled +  and rounded +
rhizomatous +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not pseudopetiolate +
pubescent +  and glabrous +
usually linear +  and lanceolate occasionally ovate +
2mm;3mm +
subdigitate +  and digitate +
15 cm150 mm <br />0.15 m <br /> (?) +
spikelike +
not woody +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.075 cm0.75 mm <br />7.5e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
triangular +  and dome--shaped +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
sometimes longer +
membranous +
Purple grama +
straight +
60 cm600 mm <br />0.6 m <br /> (80 cm800 mm <br />0.8 m <br />) +
not woody +
Maine +, Ariz. +  and N.Mex. +
not waisted +
capillary +
pistillate +  and staminate +
4-lobed +  and trilobed +
sometimes longer +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
both +  and 1 +
acuminate +
subequal +  and unequal +
papillose-based +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
not absent +
5-veined +, 7-13-veined +  and 1-3-veined +
sometimes longer +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
membranous +
membranous +
inconspicuous +
4 cm40 mm <br />0.04 m <br /> (?) +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
3-awned +  and trilobed +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
concealed +  and prominent +
2 +  and 1 +
10 cm100 mm <br />0.1 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dry +  and fleshy +
spikelike +
elongate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
flabellate +
sessile +  and subsessile +
8 +  and 11 +
terete +, compressed +  and pectinate +
1 (?) +  and 3 (?) +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Bouteloua radicosa +
Bouteloua subg. Bouteloua +
species +
membranous +
staminate +  and pistillate +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.9 cm9 mm <br />0.009 m <br /> (1 cm10 mm <br />0.01 m <br />) +
7 +  and 13 +
extended +
rhizomatous +  and stoloniferous +
plant +  and cespitose +
aquatic +  and terrestrial +