Muhlenbergia pectinata

CO. Goodd.
Common names: Combtop muhly
Treatment appears in FNA Volume 25. Treatment on page 164.

Plants annual. Culms 10-33 cm, erect or decumbent, sometimes rooting at the lower nodes; internodes glabrous. Sheaths usually longer than the internodes, glabrous, margins sparsely hairy distally, hairs to 1 mm, coarse; ligules 0.3-0.9 mm, membranous, truncate, ciliate; blades 1-6 cm long, 0.6-2 mm wide, flat to loosely involute, appressed-pubescent to sparsely pilose. Panicles 4-12 cm long, 0.5-2.6 (4) cm wide; primary branches 2-3.5 cm, appressed or diverging up to 70° from the rachises; pedicels 1-3 mm, glabrous, appressed; disarticulation above the glumes. Spikelets 2.5-5 mm, borne singly. Glumes glabrous, 1-veined, acute to acuminate, unawned or awned, awns to 1.5 mm; lower glumes 0.8-1.7 mm, entire; upper glumes 1-2 (3) mm; lemmas (2.5) 3-4.5 (5) mm, subulate to lanceolate, calluses appressed-pubescent, lemma bodies appearing 5-veined (the intermediate veins actually rows of short barbs on top of folded epidermal ridges), lateral-veins occasionally ciliate, apices acuminate, awned, awns 10-32 mm, slender, flexuous; paleas 2.4-4.4 mm, narrowly lanceolate, glabrous, acuminate; anthers 0.3-0.6 mm, yellowish. Caryopses 0.6-3.1 mm, narrowly fusiform, light brownish. 2n = 20.

Discussion

Muhlenbergia pectinata grows on rock outcrops, rocky cliffs, canyon walls, steep slopes, and road cuts, at elevations of 45-2400 m in thorn-scrub forests, gramma grasslands, and pine-oak woodlands. It is almost entirely restricted to vertical surfaces that are seasonally wet. Its range extends from southeastern Arizona to Oaxaca, Mexico.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Muhlenbergia pectinata"
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
acuminate +
Paul M. Peterson +
CO. Goodd. +
1 (?) +  and 3 (?) +
flexuous +
multiple +, , +  and single +
curled +
slender +
1 cm10 mm <br />0.01 m <br /> (3.2 cm32 mm <br />0.032 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 />) +
appressed-pubescent +  and sparsely pilose +
flat +  and loosely involute +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
spikelike +
appressed-pubescent +
light brownish +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.31 cm3.1 mm <br />0.0031 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Combtop muhly +
decumbent +  and erect +
geniculate +
10 cm100 mm <br />0.1 m <br /> (33 cm330 mm <br />0.33 m <br />) +
not waisted +
capillary +
pistillate +  and staminate +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
acute +  and acuminate +
uncinate +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
not absent +
subulate +  and lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
acuminate +  and truncate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
membranous +
inconspicuous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
concealed +  and prominent +
2 +  and 1 +
acuminate +  and lanceolate +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.44 cm4.4 mm <br />0.0044 m <br />) +
4cm +  and 12cm +
cleistogamous +
spikelike +
0.5 cm5 mm <br />0.005 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
dry +  and fleshy +
diverging;appressed +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
spikelike +
usually longer +
1 +  and 60 +
compressed +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Muhlenbergia pectinata +
Muhlenbergia +
species +
membranous +
shorter than to longer than the florets +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
7 (?) +  and 13 (?) +
stoloniferous +  and rhizomatous +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +