Burke: Poa lettermanii vs. Poa macrantha

	Poa lettermanii	Poa macrantha
	Letterman's blue grass	sand-dune blue grass
Habit		Strongly rhizomatous, dioecious perennial, the culms hollow, glabrous, 2-4 dm. tall.
Leaves		Sheaths glabrous, open most of their length, but closed as least for the lower 2-3 cm.; ligules 1-1.5 mm. long, thick, strongly pubescent, truncate, highest on the sides; blades stiff and involute, in dense basal tufts, up to 3 mm. broad, 5-12 cm. long, the tips only slightly prow-like.
Flowers		Inflorescence a compact panicle 4-12 cm. long, the branches short, stiff and ascending; spikelets 4- to 6-flowered, occasionally bulbiferous; glumes subequal, about 9 mm. long, 5-nerved, keeled; lemmas about 9 mm. long, 7- to 11-nerved, pubescent on the keel and marginal nerves, the rachilla also pubescent with soft, straight hairs; staminate flowers with anthers 3.5 mm. long, pistillate flowers with vestigial stamens.

	Poa lettermanii	Poa macrantha
Flowering time	July-September	April-July
Habitat	Mesic to wet, rocky, alpine slopes	Sand dunes along the marine coast.
Distribution	Occurring in the Cascades Range in Washington; British Columbia to California, east to the Rocky Mountains. [WildflowerSearch map] [BONAP county map]	Occurring west of the Cascades crest along the coast in Washington; southern Alaska to California. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	P. alpina, P. annua, P. arctica, P. bolanderi, P. bulbosa, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. fendleriana, P. glauca, P. howellii, P. infirma, P. interior, P. laxiflora, P. leibergii, P. leptocoma, P. macrantha, P. marcida, P. ×multnomae, P. nemoralis, P. nervosa, P. palustris, P. paucispicula, P. pratensis, P. secunda, P. stenantha, P. suksdorfii, P. trivialis, P. unilateralis, P. wheeleri	P. alpina, P. annua, P. arctica, P. bolanderi, P. bulbosa, P. compressa, P. confinis, P. curtifolia, P. cusickii, P. fendleriana, P. glauca, P. howellii, P. infirma, P. interior, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, P. marcida, P. ×multnomae, P. nemoralis, P. nervosa, P. palustris, P. paucispicula, P. pratensis, P. secunda, P. stenantha, P. suksdorfii, P. trivialis, P. unilateralis, P. wheeleri
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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

Poa macrantha

Letterman's blue grass

sand-dune blue grass

Habit

Strongly rhizomatous, dioecious perennial, the culms hollow, glabrous, 2-4 dm. tall.

Leaves

Sheaths glabrous, open most of their length, but closed as least for the lower 2-3 cm.;

ligules 1-1.5 mm. long, thick, strongly pubescent, truncate, highest on the sides;

blades stiff and involute, in dense basal tufts, up to 3 mm. broad, 5-12 cm. long, the tips only slightly prow-like.

Flowers

Inflorescence a compact panicle 4-12 cm. long, the branches short, stiff and ascending;

spikelets 4- to 6-flowered, occasionally bulbiferous;

glumes subequal, about 9 mm. long, 5-nerved, keeled;

lemmas about 9 mm. long, 7- to 11-nerved, pubescent on the keel and marginal nerves, the rachilla also pubescent with soft, straight hairs; staminate flowers with anthers 3.5 mm. long, pistillate flowers with vestigial stamens.