1	"At least some spikelets bulbiferous; plants of the high arctic tundra"	"Poa pratensis subsp. colpodea"
1	"Spikelets not bulbiferous; plants widely distributed"	2
2	"Panicle branches smooth or almost smooth"	3
2	"Panicles branches more or less scabrous"	4
3	"Basal branching primarily extravaginal; blades flat or folded, soft, adaxial surfaces usually glabrous, sometimes sparsely hairy; plants of alpine and tundra regions"	"Poa pratensis subsp. alpigena"
3	"Basal branching both intra- and extravaginal; blades folded or involute, somewhat firm, adaxial surfaces often sparsely hairy; plants widely distributed, but not in alpine or tundra regions"	"Poa pratensis subsp. agassizensis"
4	"Intravaginal innovation shoots present, intra- and extravaginal blades alike, 0.4–1 mm wide, folded to involute, somewhat firm, adaxial surfaces often sparsely and softly hairy; plants of dry meadows and forests"	"Poa pratensis subsp. angustifolia"
4	"Intravaginal innovation shoots present or absent, if present then differentiated or alike, at least some with blades 1.5–4.5 mm wide, flat or folded, adaxial surfaces rarely hairy; plants widespread, often of more mesic sites"	5
5	"Culms 8–30(50) cm tall, often somewhat glaucous, particularly the glumes; blades flat; intravaginal shoots absent or present and with blades similar to those of the extravaginal shoots; panicles with few spikelets per branch and 1–2(5) branches per node; plants of low, wet, often sandy ground"	"Poa pratensis subsp. irrigata"
5	"Culms to 100 cm tall, not glaucous; blades flat or folded; intravaginal shoots present, with blades similar to those of the extravaginal shoots or distinctly narrower; panicles with several to many spikelets per branch and 3–5(7) branches per node; plants of various habitats, including those of subsp. irrigata"	"Poa pratensis subsp. pratensis"