1	"Stems inclined with dorsi-ventral arrangement of leaves such that dorsally inserted leaves are smaller and more narrow than ventrally inserted ones; leaves typically with some hint of a limbidium"	"Epipterygium tozeri"
1	"Stems with overall erect arrangement without dorsi-ventral heterophylly; leaves typically without a limbidium"	2
2	"Leaves deeply concave with the apex broadly obtuse; leafy stems pale and glossy; cells with the walls thick and pitted"	"Anomobryum julaceum"
2	"Leaves various, keeled or not but never deeply concave; apices acute to acuminate or bluntly obtuse; leafy stems greenish and not glossy; cell walls not thick and pitted"	3
3	"Costa filling more than 1/3 of leaf base, becoming excurrent and filling leaf apex; axillary hairs with vividly reddened basal cells"	"Leptobryum pyriforme"
3	"Costa more narrow, excurrent or shorter; axillary hairs without such prominently colored basal cells"	4
4	"Plant almost stemless with costa percurrent but disappearing near its base; seta erect and red-brown bearing a slightly inclined short cylindric capsule"	"Discelium nudum"
4	"Plant with a stem 1 mm long or more; costa various but present to leaf base; seta and capsule various"	5
5	"Plants commonly with gemmae in the axils of the upper leaves; exothecial cells short-rectangular 1.5-2.5:1; capsules short, less than 2:1"	6
5	"Plants without axillary gemmae; exothecial cells isodiametric or longer than 3:1"	12
6	"Gemmae l or at most 2 per leaf axil"	7
6	"Gemmae clustered, more than 3 per leaf axil"	8
7	"Leaves spreading, more or less carinate; propagula 2-4:1, with leaf primordia on their mid-regions as well as their Apices"	"Pohlia drummondii"
7	"Leaves erect, not carinate; propagula 1-2:1 with leaf primordia restricted to their apices"	"Pohlia filum"
8	"Propagula less than 2:1 with their leaf primordia only 1-2 cells, curled over the propagulum apex, and with those propagula short-stalked"	"Pohlia camptotrachela"
8	"Propagula elongate, usually more than 6:1; leaf primordia erect to spreading, triangular and multicellular, sometimes absent; propagula stalked or not"	9
9	"Leaf primordia on propagula triangular and foliose"	10
9	"Leaf primordia absent or small geniculate to spreading peg-like structures"	11
10	"Area of leaf primordia occupying only 1/3 to 1/4 of total gemma length of the elongate gemmae"	"Pohlia tundrae"
10	"Area of leaf primordia occupying almost 1/2 of the length of the short oblong gemmae"	"Pohlia andalusica"
11	"Propagula usually with more than 2 erect leaf primordia; plants not glossy"	"Pohlia annotina"
11	"Propagula without leaf primordia or, at most, with 1-2 often geniculate structures"	"Pohlia proligera"
12	"Leaf apices somewhat cucullate at least on upper portions of stem; lower leaves on stem usually black; plant of seepages in snow-melt areas of high mountains"	"Pohlia obtusifolia"
12	"Leaf apices not cucullate; plant and leaves never blackened; plant of various habitats"	13
13	"Vegetative leaf margins recurved at least near the base"	14
13	"Vegetative leaf margins plane"	16
14	"Capsules ovoid, less than 1.5:1, with little definition of a neck; plant usually with nearly spherical, multicellular rhizoidal gemmae slightly buried or surficial near base of stem"	"Pohlia lescuriana"
14	"Capsules pyriform to cylindrical, about 2:1; gemmae unknown in California"	15
15	"Plant glaucous, tufted on seepages over schistose rocks, mostly on road cuts; peristome with exostome absent and endostome papillose"	"Mielichhoferia: various species"
15	"Plant green to yellow green; growing on moist soil in alpine areas; exostome and endostome present but without endostome cilia"	"Pohlia cardotii"
16	"Plants paroicous (look for perigonia in axils of leaves immediately below perichaetia)"	17
16	"Plants dioicous"	19
17	"Plants with a white but very glossy cast; leaves erect and overlapping, often appearing almost complanate; walls of median cells thin"	"Pohlia cruda"
17	"Plants without a whitish cast; cell walls more than 2 µm thick"	18
18	"Endostome segments perforate along the keel with the perforations 2-4:1; cilia present; broadly distributed species both in substrate and elevational occurrence, often in ruderal sites"	"Pohlia nutans"
18	"Endostome segments much more narrowly perforate, if at all; plant of very high alpine rock crevices"	"Pohlia elongata"
19	"Leaves long-decurrent; exothecial cells almost isodiametric"	20
19	"Leaves not or very little decurrent; exothecial cells longer than broad"	21
20	"Plants pale, whitish-green; median cells 12-20 µm wide"	"Pohlia wahlenbergii"
20	"Plants green to deep-green; leaves not or very little decurrent; median cells to 10 µm wide"	"Pohlia ludwigii"
21	"Leaves serrulate to low serrate near the apices"	22
21	"Leaves strongly serrate at apex"	25
22	"Plants of montane and coastal bogs; exothecial cells shorter; capsules 2-3:1, mostly pendant"	"Pohlia sphagnicola"
22	"Plants of alpine to subalpine sites; exothecial cells and capsules various"	23
23	"Capsules almost erect, 2-3:1; median laminal cells 6-8:1; stems of plant reddened"	"Pohlia erecta"
23	"Capsules inclined to pendent; median laminal cells short; stems green to red or brown"	24
24	"Stems of plant green to brown; exothecial cells long-rectangular, more than 8:1; capsules mostly more than 4:1 ascending to horizontal"	"Pohlia bolanderi"
24	"Stems of plant reddened; exothecial cells shorter; capsules 2-3:1, mostly pendent"	"Pohlia vexans"
25	"Plant vigorous with the stems 5-25 mm high; cells of exothecium isodiametric; leaves spreading, with much enlarged perichaetial bracts"	"Pohlia longibracteata"
25	"Plant smaller, stems 3-8 mm high; cells of exothecium short-rectangular with the walls strongly sinuose; leaves erect or ascending and perichaetial bracts not so strongly enlarged"	"Pohlia pacifica"