Muhlenbergia microsperma

(DC.) Trin.
Common names: Littleseed muhly
Treatment appears in FNA Volume 25. Treatment on page 162.

Plants annual, sometimes appearing as short-lived perennials; tufted. Culms 10-80 cm, often geniculate at the base, much branched near the base; internodes mostly scabridulous or smooth, always scabridulous below the nodes. Sheaths often shorter than the internodes, glabrous, smooth or scabridulous; ligules 1-2 mm, membranous to hyaline, truncate to obtuse; blades 3-8.5 (10) cm long, 1-2.5 mm wide, flat or loosely involute, scabrous abaxially, strigulose adaxially. Panicles 6.5-13.5 cm long, 1-6.5 cm wide, not dense, often purplish; branches 1.6-4 cm, ascending or diverging up to 80° from the rachises, spikelet-bearing to the base; pedicels 2-6 mm, appressed to divaricate, antrorsely scabrous; disarticulation above the glumes. Spikelets 2.5-5.5 mm, borne singly. Glumes 0.4-1.3 mm, exceeded by the florets, 1-veined, obtuse, often minutely erose; lower glumes 0.4-1 mm; upper glumes 0.6-1.3 mm; lemmas 2.5-3.8 (5.3) mm, narrowly lanceolate, mostly smooth, scabridulous distally, hairy on the calluses, lower 1/2 of the margins, and midveins, hairs 0.2-0.5 mm, apices acuminate, awned, awns 10-30 mm, straight to flexuous; paleas 2.2-4.8 mm, narrowly lanceolate, acuminate; anthers 0.3-1.2 mm, purplish. Caryopses 1.7-2.5 mm, fusiform, reddish-brown. Cleistogamous panicles with 1-3 spikelets present in the axils of the lower leaves. 2n = 20, 40, 60.

Distribution

Utah, Calif., Ariz., Pacific Islands (Hawaii), Nev.

Discussion

Muhlenbergia microsperma grows on sandy slopes, drainages, cliffs, rock outcrops, and disturbed road¬sides, at elevations of 0-2400 m. It is usually found in creosote scrub, thorn-scrub forest, sarcocaulescent desert, and oak-pinyon woodland associations. Its range extends from the southwestern United States through Central America to Peru and Venezuela. Morphological variation among and within its populations is marked.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Muhlenbergia microsperma"
60 +, 40 +  and 20 +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Paul M. Peterson +
(DC.) Trin. +
1 (?) +  and 3 (?) +
straight +  and flexuous +
multiple +, , +  and single +
curled +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
3 cm30 mm <br />0.03 m <br /> (8.5 cm85 mm <br />0.085 m <br />) +
involute +  and flat +
1mm;2.5mm +
diverging;ascending +
spikelike +
with hairs +  and glabrous +
reddish-brown +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Littleseed muhly +
geniculate +
10 cm100 mm <br />0.1 m <br /> (80 cm800 mm <br />0.8 m <br />) +
Utah +, Calif. +, Ariz. +, Pacific Islands (Hawaii) +  and Nev. +
not waisted +
capillary +
pistillate +  and staminate +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
uncinate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
scabridulous +  and smooth +
not absent +
scabridulous +
lanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
truncate +  and obtuse +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
concealed +  and prominent +
2 +  and 1 +
acuminate +  and lanceolate +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.48 cm4.8 mm <br />0.0048 m <br />) +
6.5cm +  and 13.5cm +
cleistogamous +
spikelike +
1 cm10 mm <br />0.01 m <br /> (6.5 cm65 mm <br />0.065 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
dry +  and fleshy +
spikelike +
scabridulous +  and smooth +
compressed +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
1 (?) +  and 3 (?) +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Muhlenbergia microsperma +
Muhlenbergia +
species +
membranous +
shorter than to longer than the florets +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
7 +  and 13 +
stoloniferous +  and rhizomatous +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +