OregonFlora: Muhlenbergia glomerata

	Muhlenbergia mexicana (synonym of Muhlenbergia glomerata)
	wirestem muhly
Habit	Plants perennial, 30–90 cm tall; rhizomatous.
Culms	0.5–2 mm thick; much branched above the base, not nodulose; internodes dull, puberulent or glabrous for most of their length, sometimes strigose immediately below the nodes.
Leaves	blades 2–20 cm × 2–6 mm; flat, scabrous or smooth, those of the secondary branches similar in length and width to those of the main branches.
Inflorescences	terminal and axillary, 2–21 × 0.3–3 cm; dense, appressed or diverging up to 30° from the inflorescence axis; primary branches 0.3–5.5 cm × over 0.1 mm.
Spikelets	1.5–3.8 mm, often purple-tinged.
Glumes	subequal, 1.5–3.7 mm, approximately as long as or slightly shorter than the lemmas, 1-veined, tapering from the bases to the acuminate tips; awnless or awned; awns; if present; to 2 mm.
Lemmas	1.5–3.8 mm, lanceolate, pubescent on calluses and lower portion of the midveins and margins; hairs shorter than the florets; less than 1.5 mm long; tips minutely scabrous, acuminate; awnless or awned; lemma awns 0–10 mm.
Anthers	0.3–0.5 mm; yellowish to purplish.
2n	=40.

	Muhlenbergia mexicana
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Throughout North America. 2 varieties. Muhlenbergia mexicana flowers relatively late in summer after river levels drop. It is seldom collected. The similar M. andina has lemma hairs about as long as the lemma body.
Source	Flora of Oregon, volume 1, page 435 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	M. andina, M. asperifolia, M. filiformis, M. mexicana, M. minutissima, M. richardsonis, M. uniflora
Subordinate taxa	M. mexicana var. filiformis, M. mexicana var. mexicana
Synonyms	Muhlenbergia glomerata, Muhlenbergia racemosa
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Muhlenbergia mexicana

(synonym of Muhlenbergia glomerata)

wirestem muhly

Habit

Plants perennial, 30–90 cm tall; rhizomatous.

Culms

0.5–2 mm thick; much branched above the base, not nodulose;

internodes dull, puberulent or glabrous for most of their length, sometimes strigose immediately below the nodes.

Leaves

blades 2–20 cm × 2–6 mm; flat, scabrous or smooth, those of the secondary branches similar in length and width to those of the main branches.

Inflorescences

terminal and axillary, 2–21 × 0.3–3 cm; dense, appressed or diverging up to 30° from the inflorescence axis;

primary branches 0.3–5.5 cm × over 0.1 mm.

Spikelets

1.5–3.8 mm, often purple-tinged.

Glumes

subequal, 1.5–3.7 mm, approximately as long as or slightly shorter than the lemmas, 1-veined, tapering from the bases to the acuminate tips; awnless or awned; awns; if present; to 2 mm.

Lemmas

1.5–3.8 mm, lanceolate, pubescent on calluses and lower portion of the midveins and margins;

hairs shorter than the florets; less than 1.5 mm long;

tips minutely scabrous, acuminate; awnless or awned;

lemma awns 0–10 mm.

Anthers

0.3–0.5 mm; yellowish to purplish.

=40.

Muhlenbergia mexicana

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Throughout North America. 2 varieties.

Muhlenbergia mexicana flowers relatively late in summer after river levels drop. It is seldom collected. The similar M. andina has lemma hairs about as long as the lemma body.

Source

Flora of Oregon, volume 1, page 435
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa