Burke: Poa cusickii vs. Poa bulbosa

	Poa cusickii	Poa bulbosa
	Cusick's bluegrass	bulbous bluegrass
Habit	Smooth, strongly tufted perennial, the culms hollow, 2-4 dm. tall.	Strongly tufted, glabrous perennial, the culms hollow, 1.5-4 dm. tall.
Leaves	Sheaths closed about half their length; ligules 1-3 mm. long, acute, jagged, glabrous; blades of the fertile stems 1-3.5 mm. broad, flat; blades of the sterile stems 0.5-1 mm. broad, involute, often 1-2 dm. long; all blades with prow-like tips.	Sheaths open almost to the base; ligules 1.5-3 mm. long, blunt to acuminate, usually entire; blades 1-2.5 mm. broad, flat to folded, scabrous, the tip prow-like.
Flowers	Inflorescence a compact, ovoid panicle 2-6 cm. long, greenish or purplish; spikelets 3- to 5-flowered, 5-8 mm. long; flowers usually pistillate, the anthers vestigial or wanting, but occasionally the plants staminate- or perfect-flowered; glumes subequal, 3-nerved, 3.5-5 mm. long, shorter than the first floret; lemmas keeled, 5-nerved, 4.5-6 mm. long, pubescent; paleas slightly shorter than the lemmas, 2-keeled.	Inflorescence an open to contracted panicle up to 10 cm. long; spikelets 3-5 mm. long, but florets usually modified into elongate, purplish bulbils up to 20 mm. long; glumes 2-3 mm. long; normal lemmas about 5 per spikelet, keeled, 2-4 mm. long, webbed at base; viviparous spikelets modified into a single bulbil enclosed by the several leaf-like lemmas 5-20 mm. long; stamens and pistils mostly lacking.

	Poa cusickii	Poa bulbosa
Flowering time	May-August	March-June
Habitat	Sagebrush plains to alpine meadows and ridges.	Disturbed areas from the coast to midmontane.
Distribution	Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Saskatchewan and Colorado. [WildflowerSearch map] [BONAP county map]	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Native	Introduced
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. fendleriana, P. glauca, P. howellii, P. infirma, P. interior, P. laxiflora, P. leibergii, P. leptocoma, P. lettermanii, 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. 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. 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
Subordinate taxa	P. cusickii ssp. cusickii, P. cusickii ssp. epilis, P. cusickii ssp. pallida, P. cusickii ssp. purpurascens	P. bulbosa ssp. vivipara
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 bulbosa

Cusick's bluegrass

bulbous bluegrass

Habit

Smooth, strongly tufted perennial, the culms hollow, 2-4 dm. tall.

Strongly tufted, glabrous perennial, the culms hollow, 1.5-4 dm. tall.

Leaves

Sheaths closed about half their length;

ligules 1-3 mm. long, acute, jagged, glabrous;

blades of the fertile stems 1-3.5 mm. broad, flat;

blades of the sterile stems 0.5-1 mm. broad, involute, often 1-2 dm. long; all blades with prow-like tips.

Sheaths open almost to the base;

ligules 1.5-3 mm. long, blunt to acuminate, usually entire;

blades 1-2.5 mm. broad, flat to folded, scabrous, the tip prow-like.

Flowers

Inflorescence a compact, ovoid panicle 2-6 cm. long, greenish or purplish;

spikelets 3- to 5-flowered, 5-8 mm. long;

flowers usually pistillate, the anthers vestigial or wanting, but occasionally the plants staminate- or perfect-flowered;

glumes subequal, 3-nerved, 3.5-5 mm. long, shorter than the first floret;

lemmas keeled, 5-nerved, 4.5-6 mm. long, pubescent;

paleas slightly shorter than the lemmas, 2-keeled.

Inflorescence an open to contracted panicle up to 10 cm. long;

spikelets 3-5 mm. long, but florets usually modified into elongate, purplish bulbils up to 20 mm. long;

glumes 2-3 mm. long; normal lemmas about 5 per spikelet, keeled, 2-4 mm. long, webbed at base; viviparous spikelets modified into a single bulbil enclosed by the several leaf-like lemmas 5-20 mm. long;

stamens and pistils mostly lacking.