Muhlenbergia depauperata

Scribn.
Common names: Sixweeks muhly
Treatment appears in FNA Volume 25. Treatment on page 196.

Plants annual; tufted. Culms 3-15 cm; internodes mostly scabridulous or pubescent, pubescent or strigose below the nodes. Sheaths often longer than the internodes, somewhat inflated, smooth or scabrous, keeled, margins scarious, not flattened, papery, or spirally coiled when old; ligules 1.4-2.5 mm, membranous, acute, with lateral lobes; blades 1-3 cm long, 0.6-1.5 mm wide, flat or involute, scabrous to strigose, midveins and margins thickened, whitish. Panicles 2.5-8.5 cm long, 0.5-0.7 cm wide, contracted; primary branches 1-2.2 cm, appressed, spikelet-bearing to the base, spikelets borne in subsessile-pedicellate pairs; longer pedicels 3-6 mm, scabrous; disarticulation beneath the spikelet pairs. Spikelets 2.5-5.1 mm, appressed. Glumes 2.3-5.1 mm, equaling or exceeding the florets; lower glumes 2.3-4 mm, subulate, 2-veined, minutely to deeply bifid, teeth aristate or with awns to 1.3 mm; upper glumes 3-5.1 mm, lanceolate, 1-veined, entire, acuminate; lemmas 2.5-4.5 mm, narrowly lanceolate, light greenish-brown to purplish, scabrous, appressed-pubescent on the margins and midveins, apices acuminate, awned, awns 6-15 mm, stiff; paleas 2.4-3.6 mm, lanceolate, intercostal region appressed-pubescent, apices acuminate; anthers 0.5-0.8 mm, purplish to yellowish. Caryopses 1.5-2.3 mm, narrowly fusiform, brownish. 2n = 20.

Distribution

Utah, Ariz., Colo., N.Mex., Tex.

Discussion

Muhlenbergia depauperata grows in gravelly flats, rock outcrops, exposed bedrock, and sandy banks, in gramma grassland associations, usually on soils derived from calcareous parent materials, at elevations of 1530-2400 m. Its range extends from the southwestern United States to southern Mexico.

Muhlenbergia depauperata and M. brevis share several features with Lycurus: spikelets borne in pairs, 2-veined and 2-awned lower glumes, 1-veined and awned upper glumes, acuminate, awned lemmas with short pubescence along the margins, and pubescent paleas.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Muhlenbergia depauperata"
purplish +  and yellowish +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
acuminate +
Paul M. Peterson +
Scribn. +
1 (?) +  and 3 (?) +
sinuous +, flexuous +  and straight +
multiple +, , +  and single +
curled +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 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 /> (3 cm30 mm <br />0.03 m <br />) +
scabrous +  and strigose +
involute +  and flat +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
spikelike +
with hairs +  and glabrous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Sixweeks muhly +
geniculate +
3 cm30 mm <br />0.03 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Utah +, Ariz. +, Colo. +, N.Mex. +  and Tex. +
not waisted +
capillary +
pistillate +  and staminate +
bisexual +  and fertile +
round +  and compressed +
reduced +
(0)1(2-3)-veined +
shorter or longer +
subtending +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.51 cm5.1 mm <br />0.0051 m <br />) +
exceeding the florets +  and equaling +
uncinate +
paniculate +  and racemose +
appressed-pubescent +
hollow +  and solid +
strigose +  and pubescent +
scabridulous +
not absent +
light greenish-brown +  and purplish +
appressed-pubescent +
lanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
membranous +
inconspicuous +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
not flattened +
papery +  and scarious +
concealed +  and prominent +
2 +  and 1 +
subsessile-pedicellate +
lanceolate +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
2.5cm +  and 8.5cm +
cleistogamous +
spikelike +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
dry +  and fleshy +
1 cm10 mm <br />0.01 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
spikelike +
keeled +  and inflated +
1 +  and 60 +
compressed +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.51 cm5.1 mm <br />0.0051 m <br />) +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Muhlenbergia depauperata +
Muhlenbergia +
species +
membranous +
with awns +  and aristate +
shorter than to longer than the florets +
acuminate +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.51 cm5.1 mm <br />0.0051 m <br />) +
7 (?) +  and 13 (?) +
stoloniferous +  and rhizomatous +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +