Muhlenbergia rigens

(Benth.) Hitchc.
Common names: Deergrass
Synonyms: Muhlenbergia mundula Muhlenbergia marshii Epicampes rigens
Treatment appears in FNA Volume 25. Treatment on page 194.

Plants perennial; cespitose, not rhizomatous. Culms (35) 50-150 cm tall, to 5 mm thick near the base, stiffly erect, not rooting at the lower nodes; internodes glabrous. Sheaths longer than the internodes, smooth or scabridulous, rounded dorsally, bases somewhat flat and chartaceous; ligules 0.5-2 (3) mm, firm, truncate, usually ciliolate; blades 10-50 cm long, 1.5-6 mm wide, flat or involute, stiff, glabrous abaxially, scabrous adaxially. Panicles 15-60 cm long, 0.5-1.2 cm wide, spikelike, dense, grayish-green, often interrupted below; primary branches 0.2-4 cm, appressed; pedicels 0.2-3 mm, hispidulous, strongly divergent. Spikelets 2.4-4 mm. Glumes subequal, 1.8-3.2 mm, almost as long as the florets, scabrous to scabridulous, 1-veined, usually acute or obtuse, occasionally acuminate or notched, occasionally mucronate, mucros to 0.6 mm; lemmas 2.4-4 mm, lanceolate, pubescent on the calluses, lower 1/6 of the margins, and midveins, hairs to 0.4 mm, apices scabrous, acute or obtuse, unawned, rarely mucronate, mucros to 1 mm; paleas 2.3-3.8 mm, lanceolate, acute; anthers 1.3-1.8 mm, yellow to purple. Caryopses 1.8-2.2 mm, fusiform, brownish. 2n = 40.

Distribution

Calif., Ariz., N.Mex., Nev., Tex.

Discussion

Muhlenbergia rigens grows in sandy washes, gravelly canyon bottoms, rocky drainages, and moist, sandy slopes, often along small streams, at elevations of 90-2500 m. Its geographic range extends to central Mexico. It is available commercially as an ornamental. Muhlenbergia rigens is similar to M. dubia, but differs in having tighter, spikelike panicles, shorter ligules, yellow or purplish anthers, and shorter lemmas.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Muhlenbergia rigens"
yellow +  and purple +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
awned +  and entire +
mucronate +, obtuse +  and acute +
Paul M. Peterson +
(Benth.) Hitchc. +
1 (?) +  and 3 (?) +
sinuous +, flexuous +  and straight +
multiple +, , +  and single +
curled +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
10 cm100 mm <br />0.1 m <br /> (50 cm500 mm <br />0.5 m <br />) +
involute +  and flat +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spikelike +
with hairs +  and glabrous +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Deergrass +
not rooting +
50 cm500 mm <br />0.5 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
geniculate +
2 cm20 mm <br />0.02 m <br /> (300 cm3,000 mm <br />3 m <br />) +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Calif. +, Ariz. +, N.Mex. +, Nev. +  and Tex. +
not waisted +
capillary +
pistillate +  and staminate +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
scabrous +  and scabridulous +
mucronate +, notched +, acuminate +, obtuse +  and acute +
subequal +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
uncinate +
0 cm0 mm <br />0 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
not absent +
lanceolate +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
acuminate +  and truncate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
inconspicuous +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
concealed +  and prominent +
2 +  and 1 +
acute +  and lanceolate +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
grayish-green +
15cm +  and 60cm +
cleistogamous +
spikelike +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
dry +  and fleshy +
0.2 cm2 mm <br />0.002 m <br /> (4 cm40 mm <br />0.04 m <br />) +
spikelike +
scabridulous +  and smooth +
1 +  and 60 +
compressed +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Muhlenbergia mundula +, Muhlenbergia marshii +  and Epicampes rigens +
Muhlenbergia rigens +
Muhlenbergia +
species +
membranous +
shorter than to longer than the florets +
7 (?) +  and 13 (?) +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +