Muhlenbergia arsenei

Hitchc.
Common names: Navajo muhly
Treatment appears in FNA Volume 25. Treatment on page 169.

Plants perennial; rhizomatous, rhizomes sometimes short and the plants loosely cespitose. Culms 10-50 cm tall, 0.4-1 mm thick, decumbent; internodes glabrous or strigulose. Sheaths shorter than the internodes, strigulose or glabrous, usually without necrotic spots, not becoming spirally coiled when old; ligules 1-2 mm, membranous throughout, obtuse, strigulose or glabrous, erose or toothed, with lateral lobes, lobes less than 1.5 mm longer than the central portion; blades 1-6 cm long, 1-2 mm wide, flat to involute, smooth or scabridulous abaxially, hirsute adaxially, usually without necrotic spots. Panicles 4-13 cm long, 1-3 (5) cm wide, not dense; primary branches 0.5-4 cm, appressed or diverging up to 30° from the rachises, spikelet-bearing to the base; pedicels 0.1-3 mm. Spikelets 3.5-5 mm. Glumes subequal, 2-4 mm, exceeded by the florets, 1-veined, scabrous on the veins and near the apices, apices acuminate, unawned or awned, awns to 1.2 mm; lemmas 3.5-5 mm, lanceolate, mostly purplish, veins conspicuously green, pubescent on the lower 1/3-1/2 of the midveins and margins, hairs to 1.5 mm, apices scabridulous, acuminate, awned, awns 4-12 (20) mm, flexuous; paleas 3.5-5 mm, narrow-lanceolate, intercostal region pubescent, apices acuminate, veins sometimes extending into awns to 0.5 mm; anthers 1.3-3 mm, purple. Caryopses 2-2.3 mm, fusiform, brownish. 2n = unknown.

Distribution

Utah, Calif., N.Mex., Nev.

Discussion

Muhlenbergia arsenei grows among granitic boulders, on rocky slopes, limestone rock outcrops, and in arroyos, at elevations of 1400-2850 m. Its range extends from the southwestern United States into Baja California, Mexico. It flowers from August to September.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Muhlenbergia arsenei"
olivaceous +, yellow +, orange +  and purple +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
scabridulous +
Paul M. Peterson +
Hitchc. +
1 (?) +  and 3 (?) +
20 cm200 mm <br />0.2 m <br /> (?) +
flexuous +
multiple +, , +  and single +
curled +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
1 cm10 mm <br />0.01 m <br /> (6 cm60 mm <br />0.06 m <br />) +
scabridulous +  and smooth +
flat +  and involute +
1mm;2mm +
spikelike +
with hairs +  and glabrous +
0.2 cm2 mm <br />0.002 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Navajo muhly +
10 cm100 mm <br />0.1 m <br /> (50 cm500 mm <br />0.5 m <br />) +
geniculate +
2 cm20 mm <br />0.02 m <br /> (300 cm3,000 mm <br />3 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Utah +, Calif. +, N.Mex. +  and Nev. +
not waisted +
capillary +
pistillate +  and staminate +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
subequal +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
uncinate +
0 cm0 mm <br />0 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
strigulose +  and glabrous +
not absent +
lanceolate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
glabrous +  and strigulose +
toothed +  and obtuse +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
concealed +  and prominent +
2 +  and 1 +
narrow-lanceolate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
4cm +  and 13cm +
cleistogamous +
spikelike +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
dry +  and fleshy +
diverging;appressed +
0.5 cm5 mm <br />0.005 m <br /> (4 cm40 mm <br />0.04 m <br />) +
spikelike +
glabrous +  and strigulose +
1 +  and 60 +
compressed +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 (?) +  and 3 (?) +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Muhlenbergia arsenei +
Muhlenbergia +
species +
membranous +
shorter than to longer than the florets +
7 +  and 13 +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +