Muhlenbergia richardsonis |
Muhlenbergia torreyi |
|
---|---|---|
mat muhly, Matted muhly, muhlenbergie de Richardson, Richardson's muhly, soft-leaf muhly |
ring muhly |
|
Habit | Plants perennial; rhizomatous, not cespitose, often mat-forming. | Plants perennial; cespitose, not rhizomatous. |
Culms | 5-30 cm tall, 0.4-1 mm thick, decumbent, geniculate, or erect; internodes usually nodulose (occasionally smooth) for most of their length, puberulent or nodulose below the nodes. |
10-40(50) cm, decumbent, usually all the nodes concealed by the sheaths; internodes mostly scabrous or smooth, hispidulous below the nodes. |
Sheaths | shorter or longer than the internodes, glabrous; ligules 0.8-3 mm, membranous, acute to truncate, erose; blades 0.4-6.5 cm long, 0.5-4.2 mm wide, flat or involute, straight or arcuate-spreading, glabrous abaxially, hirtellous adaxially. |
|
Leaves | strongly basally concentrated, most blades not reaching more than 1/5 of the plant height; sheaths shorter than the internodes, rounded, not keeled, scabridulous or smooth, not becoming spirally coiled when old; ligules 2-5(7) mm, hyaline, acuminate, lacerate, often with lateral lobes; blades 1-3(5) cm long, 0.3-0.9 mm wide, tightly involute or folded, arcuate, scabridulous, midveins and margins not thickened, green, apices somewhat sharp-pointed. |
|
Panicles | 1-15 cm long, 0.1-1.7 cm wide, exserted, narrow or spikelike, rachises usually concealed by the branches; primary branches 0.4-5 cm, usually closely appressed at maturity, rarely diverging up to 20° from the rachises; pedicels 0.2-2 mm, setulose. |
7-21 cm long, 3-15 cm wide, diffuse; primary branches 1-8 cm, diverging 30-90° from the rachises, stiff, naked basally; pedicels 1-8 mm, sometimes appressed to the branches. |
Spikelets | 1.7-3.1 mm, occasionally with 2 florets. |
2-3.5 mm. |
Glumes | subequal, 0.6-2 mm, 1/3– 1/2 as long as the lemmas, green, 1(2)-veined, acute, sometimes mucronate, mucros less than 0.2 mm; lemmas 1.7-2.6(3.1) mm, lanceolate, dark greenish, plumbeous, or mottled, glabrous, apices scabridulous, acute to acuminate, sometimes mucronate, mucros to 0.5 mm; paleas 1.2-2.4(2.9) mm, lanceolate, acute; anthers 0.9-1.6 mm, yellow to purplish. |
equal, 1.3-2.5 mm, scabridulous, 1-veined, apices acute to acuminate, minutely erose, unawned or awned, awns to 1.1 mm; lemmas 2-3.2(3.5) mm, narrowly elliptic to lanceolate, appressed-pubescent on the basal 1/2 - 3/4 of the margins and midveins, apices scabrous, acuminate, awned, awns 0.5-4 mm; paleas 2-3.2(3.5) mm, narrowly elliptic, intercostal region sparsely pubescent, apices acuminate; anthers 1.2-2.1 mm, greenish. |
Caryopses | 0.9-1.6 mm, narrowly ellipsoid, brown. |
1.7-2 mm, fusiform, brownish. |
2n | = 40. |
= 20, 21. |
Muhlenbergia richardsonis |
Muhlenbergia torreyi |
|
Distribution |
AK; AZ; CA; CO; ID; ME; MI; MN; MT; ND; NE; NM; NV; OR; SD; UT; WA; WI; WY; AB; BC; MB; NB; NT; ON; QC; SK; YT
|
AZ; CO; KS; NM; NV; OK; TX; WY
|
Discussion | Muhlenbergia richardsonis grows in open sites in alkaline meadows, prairies, sandy arroyo bottoms, talus slopes, rocky flats and the shores of rivers, at elevations of 60-3300 m. It is the most widespread species of Muhlenbergia in the Flora region, extending from the Yukon Territory to Quebec in the north and to northern Baja California, Mexico, in the south. Morden and Hatch (1996) reported that it also grows in Alaska, but no voucher specimen has been located. Muhlenbergia richardsonis is often confused with M. cuspidata, which differs in lacking rhizomes and having shorter ligules, and sometimes with M. filiformis, which differs in being a weak annual with glabrous internodes and obtuse, erose glumes. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Muhlenbergia torreyi grows in desert grasslands and open woodlands on sandy mesas, calcareous rock out-crops, and rocky slopes, at elevations of 1000-2450 m. Its range extends from the southwestern United States to northern Mexico. It also grows, as a disjunct, in northwestern Argentina. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 177. | FNA vol. 25, p. 173. |
Parent taxa | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Muhlenbergia | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Muhlenbergia |
Sibling taxa | ||
Synonyms | Sporobolus depauperatus, M. squarrosa | |
Name authority | (Trin.) Rydb. | (Kunth) Hitchc. ex Bush |
Web links |
|