Muhlenbergia mexicana |
Muhlenbergia tenuifolia |
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Mexican muhly, muhlenbergie du mexique, muhlenbergie mexicaine, wire-stem muhly, wood satin grass |
mesa muhly, slender muhly |
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Habit | Plants perennial; rhizomatous, not cespitose. | Plants annual or short-lived perennials; cespitose, not rhizomatous. |
Culms | 30-90 cm tall, 0.5-2 mm thick, erect, much branched above the base; internodes dull, puberulent or glabrous for most of their length, sometimes strigose immediately below the nodes. |
20-70 cm, erect or decumbent; internodes mostly scabridulous or smooth, always scabridulous below the nodes. |
Sheaths | smooth or scabridulous, somewhat keeled; ligules 0.4-1 mm, membranous, truncate, lacerate-ciliolate; blades 2-20 cm long, 2-6 mm wide, flat, scabrous or smooth, those of the secondary branches similar in length and width to those of the main branches. |
usually shorter than the internodes, glabrous, smooth or scabridulous, usually without necrotic spots, not becoming spirally coiled when old; ligules 1.2-3(5) mm, membranous throughout, acute, often lacerate; blades 2-13 cm long, 1.2-2.5 mm wide, flat or loosely involute, scabridulous or glabrous abaxially, scabrous adaxially, usually without necrotic spots. |
Panicles | terminal and axillary, 2-21 cm long, 0.3-3 cm wide, dense; primary branches 0.3-5.5 cm, appressed or diverging up to 30° from rachises; pedicels to 2 mm, strigose; axillary panicles exserted on long peduncles. |
numerous, terminal and axillary, 7-20 cm long, 0.3-1.4(3) cm wide, contracted, often lax, nodding, interrupted below; primary branches 3.5-7.5 cm, ascending or diverging up to 70° from the rachises, spikelet-bearing to the base; pedicels 1-3 mm, antrorsely scabrous; disarticulation above the glumes. |
Spikelets | 1.5-3.8 mm, often purple-tinged. |
2-4 mm, often purplish, borne singly. |
Glumes | subequal, 1.5-3.7 mm, equaling or slightly shorter than the lemmas, 1-veined, tapering from the bases to the acuminate apices, unawned or awned, awns to 2 mm; lemmas 1.5-3.8 mm, lanceolate, pubescent on the calluses, lower portion of the mid-veins, and margins, hairs shorter than 0.7 mm, apices scabridulous, acuminate, unawned or awned, awns to 10 mm; paleas 1.5-3.8 mm, narrowly lanceolate, apices acuminate; anthers 0.3-0.5 mm, yellow to purplish. |
1.2-2.8 mm, shorter than the florets, 1-veined, veins scabrous, apices often erose, unawned or awned, awns to 0.5 mm; lower glumes 1.2-2 mm, acute to acuminate; upper glumes 1.5-2.8 mm, acute; lemmas 2-3.5(4) mm, lanceolate, mostly smooth, scabridulous distally, pubescent on the calluses, lower 1/2 of the midveins, and margins, hairs 0.5-1.5 mm, apices acuminate to acute, awned, awns 10-30 mm, scabrous, sinuous to flexuous; paleas 1.8-3.4(3.8) mm, lanceolate, sparsely villous basally, apices acuminate to acute; anthers 0.9-1.5 mm, yellowish. |
Caryopses | 1.1-1.6 mm, fusiform, brown. |
1-2.2 mm, narrowly fusiform, brownish. |
Cleistogamous | panicles not present. |
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2n | = 40. |
= 20, 40. |
Muhlenbergia mexicana |
Muhlenbergia tenuifolia |
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Distribution |
AL; AR; AZ; CA; CO; CT; DE; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; HI; BC; MB; NB; NS; ON; QC; SK; YT
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AZ; NM; TX
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Discussion | Muhlenbergia mexicana usually grows in mesic to wet areas such as moist prairies and woodlands, stream banks, roadsides, ditch banks, lake margins, swamps, bogs, and hot springs, at elevations 50-3300 m, and is found in many different plant communities. Despite its name, M. mexicana grows only in Canada and the United States. Plants with awns 3-10 mm long belong to Muhlenbergia mexicana var. filiformis (Torr.) Scribn., and those without an awn or with awns less than 3 mm long to Muhlenbergia mexicana (L.) Trin. var. mexicana. Early in the flowering season, M. mexicana may be confused with plants of M. bushii in which the axillary panicles are poorly developed, but they differ in their dull internodes and the fact that the blades on the secondary branches are usually similar in length and width to those of the main branches. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Muhlenbergia tenuifolia grows in gramma grasslands and pine-oak woodlands on rocky slopes, limestone rock outcrops, gravelly roadsides, and in sandy drainages, at elevations of 1200-2200 m. Its range extends through Mexico to northern South America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 154. | FNA vol. 25, p. 162. |
Parent taxa | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Muhlenbergia | Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Muhlenbergia |
Sibling taxa | ||
Synonyms | M. monticola | |
Name authority | (L.) Trin. | (Kunth) Trin. |
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