1	Hyaline cortical cells of stems and branches with spiral fibrils and pores; branch leaves broadly ovate, cucullate-concave, rounded and dorsally roughened at the apex		(2)
+	Hyaline cortical cells of stems and branches without spiral fibrils, sometimes with pores; branch leaves generally narrowly ovate, not cucullate-concave, truncate, not dorsally roughened at the apex		(9)
2 (1)	Green cells of branch leaves in cross section centrally located and entirely enclosed by large, hyaline cells on both surfaces		21 Sphagnum magellanicum
+	Green cells of branch leaves in cross section exposed on 1 or both surfaces		(3)
3 (2)	Cortical cells of stems with a single pore on the external walls; green cells in cross section narrowly elliptic, exposed equally on both surfaces		29 Sphagnum perichaetiale
+	Cortical cells of stems with 2 to several pores on the external walls; green cells in cross section triangular, exposed entirely or more broadly on the ventral surface		(4)
4 (3)	Cortical cells of branches funnel-shaped and nested together at base, without pores on the external walls; branches club-shaped; branch leaves 4–6 times larger than stem leaves		32 Sphagnum portoricense
+	Cortical cells of branches not funnel-shaped and plane at base, with several pores on the external walls; branches not club-shaped; branch leaves more or less as long as stem leaves		(5)
5 (4)	Hyaline cells of stem leaves usually divided; the inner walls of hyaline cells adjacent to the green cells of branch leaves in cross section densely papillose or with fringe-fibrils		(6)
+	Hyaline cells of stem leaves undivided; the inner walls of hyaline cells adjacent to the green cells of branch leaves in cross section smooth		(7)
6 (5)	Cortical cells of stems with numerous pores on the external walls; green cells of branch leaves in cross section isosceles-triangular, the adjacent walls of hyaline cells often with dense fringe-fibrils		14 Sphagnum imbricatum
+	Cortical cells of stems often with 2 pores on the external walls; green cells of branch leaves in cross section trapezoidal to nearly triangular, the adjacent walls of hyaline cells often with papillae		28 Sphagnum papillosum
7 (5)	Stem leaves plane, oblong-ligulate, more than 2 times as long as wide, hyaline cells densely reinforced by spiral fibrils and pores		23 Sphagnum multifibrosum
+	Stem leaves concave, short-ligulate, less than 1.5 times as long as wide, hyaline cells without fibrils or only with thickenings on the walls		(8)
8 (7)	Stems and branches long and slender; green cells of branch leaves narrowly triangular		27a Sphagnum palustre ssp. palustre
+	Stems and branches short and stout; green cells of branch leaves equilaterally triangular		27b Sphagnum palustre ssp. pseudocymbifolium
9 (1)	Green cells of branch leaves in cross section narrowly elliptic, centrally located		(10)
+	Green cells of branch leaves in cross section mostly triangular or trapezoidal, exposed on either the ventral side or the dorsal side of leaves		(21)
10 (9)	Branches in fascicles of 6–12; capitulum noticeably large and dense; branch leaves widely recurved when dry		46 Sphagnum wulfianum
+	Branches in fascicles of 5 or fewer; capitulum not noticeably large or dense; branch leaves not widely recurved when dry		(11)
11 (10)	Branch leaves more or less as long as the stem leaves		(12)
+	Branch leaves 1.5–2 times or up to 4 times longer than the stem leaves		(14)
12 (11)	Stem leaves triangular-ligulate, hyaline cells often divided; fascicles usually rather distantly set		30 Sphagnum platyphylloides
+	Stem leaves ovate-ligulate, hyaline cells undivided; fascicles usually closely set		(13)
13 (12)	Plants stiff; stem leaves cucullate-concave, without pores at the apex, hyaline cells with pores not located at the opposite sides on the ventral surface		18 Sphagnum khasianum
+	Plants soft; stem leaves involute-concave, with pores at the apex, hyaline cells with pores located at the opposite sides on the ventral surface		26 Sphagnum ovatum
14 (11)	Plants yellowish green tinged with purple; fascicles densely set, concealing stems; cortical cells of branches uniform, each with 1 pore at the upper end; branch leaves usually 4 times larger than stem leaves		5 Sphagnum compactum
+	Plants light green to grayish green; fascicles usually rather distantly set; cortical cells of branches 2 kinds, some without pores, others with enlarged, retort-shaped, apically located pores; branch leaves 1.5–2 times larger than stem leaves		(15)
15 (14)	Branch leaves narrowly ovate, tapered and involute at the apex; borders of stem leaves not widened below, nearly even throughout		22 Sphagnum microporum
+	Branch leaves broadly ovate to oblong-ovate, cucullate-concave at the apex; borders of stem leaves narrowed above, gradually to suddenly widened below		(16)
16 (15)	Stem leaves with borders strongly widened below (ca. 1/4 leaf base); branch leaves broadly ovate and strongly concave, with straight, truncate and dentate apices		3 Sphagnum aongstroemii
+	Stem leaves with borders gradually widened below; branch leaves oblong-ovate and moderately concave, with upcurved-secund and not dentate apices		(17)
17 (16)	Stem cortex in 1 layer		(18)
+	Stem cortex in 2 or more layers		(20)
18 (17)	Stem leaves less than ½ as long as branch leaves, with fibrils and pores only at the apex		42 Sphagnum subsecundum
+	Stem leaves more than ½ as long as branch leaves, with fibrils and pores developed below the apex		(19)
19 (18)	Stem leaves fibrillose in the upper ½ or less, without or with few pores on the dorsal surface, several to many pores on the ventral surface		15 Sphagnum inundatum
+	Stem leaves fibrillose in the upper ½ –2/3, with many pores on the dorsal surface, without or with few pores on the ventral surface		9 Sphagnum denticulatum
20 (17)	Terminal buds not notably large; branches differentiated into spreading and pendent types, concealing the stems, with secund leaves; stem leaves clearly smaller than branch leaves; hyaline cells of branch leaves without or with few pores on the ventral surface		6 Sphagnum contortum
+	Terminal buds distinctly large; branches not clearly differentiated into spreading and pendent types, not concealing the stems, with imbricate leaves; stem leaves as long as branch leaves; hyaline cells of branch leaves with many pores on the ventral surface		31 Sphagnum platyphyllum
21 (9)	Green cells of branch leaves mostly trapezoidal, exposed on the ventral surface		(22)
+	Green cells of branch leaves mostly triangular, exposed on the dorsal surface		(34)
22 (21)	Hyaline cells of branch leaves without spiral fibrils; stem and branch leaves apiculate		39 Sphagnum sericeum
+	Hyaline cells of branch leaves with spiral fibrils; stem leaves round-obtuse to acuminate; branch leaves truncate at the apex		(23)
23 (22)	Stem leaves fimbriate or lacerate-fringed across the broad apex, with a sieve-like triangular area of resorption at the middle of leaf base		13 Sphagnum girgensohnii
+	Stem leaves entire or toothed, sometimes only slightly fimbriate across a portion of the apex, without sieve-like area at the middle of leaf base		(24)
24 (23)	Hyaline cortical cells of stems with pores		(25)
+	Hyaline cortical cells of stems without pores		(29)
25 (24)	Stem leaves ligulate, hyaline cells with pores only near the apices		(26)
+	Stem leaves triangular, hyaline cells usually porous		(27)
26 (25)	Branch leaves ovate-lanceolate, abruptly narrowed to a channelled and squarrose apex		38 Sphagnum russowii
+	Branch leaves oblong-lanceolate, gradually narrowed toward a straight apex		37 Sphagnum rubellum
27 (25)	Borders of stem leaves narrowly developed above, clearly widened below; spreading branches often in group of 3; branch leaves usually in 5 ranks, oblong-lanceolate with a straight apex		34 Sphagnum quinquefarium
+	Borders of stem leaves narrowly and evenly differentiated throughout the margins; spreading branches not in group of 3; branch leaves not in clearly 5 ranks, broadly ovate-lanceolate with a squarrose apex		(28)
28 (27)	Plants more robust; stem leaves ca. 1.8 mm long; branch leaves 1.5–2.0 mm long; stem cortical cells freely porous; hyaline cells of stem leaves with commissural pores on both surfaces		17a var. junghuhnianum
+	Plants soft, slender; stem leaves ca. 1.0 mm long; branch leaves ca. 1.3 mm long; stem cortical cells often without pores or only with large, single pore in some cells; upper hyaline cells of stem leaves without pores, lower hyaline cells with a few pores on the ventral surface		17b var. pseudomolle
29 (24)	Stem leaves oblong-ligulate with a broadly rounded apex, marginal borders distinctly widened at base		(30)
+	Stem leaves oblong-triangular with a broadly acute to cucullate-concave apex, marginal borders not distinctly widened at base		(31)
30 (29)	Branch leaves usually not in rows and not recurved at the tips, upper hyaline cells with large, elliptic, moderately ringed pores		12 Sphagnum fuscum
+	Branch leaves often in 5 rows and recurved at the tips, upper hyaline cells with minute, rounded to rounded-elliptic, strongly ringed pores		45 Sphagnum warnstorfii
31 (29)	Plants shiny when dry, bluish or purple-brown when moist; hyaline cells of stem leaves without fibrils		(32)
+	Plants not shiny when dry, often red or pink when moist; hyaline cells of stem leaves frequently with fibrils, more fibrils in the upper cells		(33)
32 (31)	Margins of stem leaves narrowly and evenly bordered throughout, hyaline cells with numerous pores on the ventral surface; branch leaves abruptly narrowed from a broadly ovate base to a cucullate apex		1 Sphagnum acutifolioides
+	Margins of stem leaves narrowly bordered above, clearly widened at base, hyaline cells without pores on both surfaces; branch leaves gradually narrowed from an oblong-ovate base to a channeled apex		41 Sphagnum subnitens
33 (31)	Stem leaves with cucullate-concave and pointed apices, upper hyaline cells with 1–2 pores on the dorsal surface; plants usually red		4 Sphagnum capillifolium
+	Stem leaves with broadly obtuse to rounded apices, hyaline cells without pores or rarely with 1 pore in some upper cells on the dorsal surface; plants usually pink		24 Sphagnum obtusiusculum
34 (21)	Stem leaves ligulate with broad, dentate apices, hyaline cells mostly resorbed on the dorsal surface; branch leaves not undulate when dry, more or less squarrose at acumen, hyaline cells papillose on the inner walls adjacent to the green cells		(35)
+	Stem leaves triangular to triangular-ligulate with narrow apices, hyaline cells mostly resorbed on the ventral surface; branch leaves often undulate when dry, not squarrose at acumen, hyaline cells smooth on the inner walls adjacent to the green cells		(36)
35 (34)	Plants monoicous, robust; perichaetial leaves clearly smaller than branch leaves; branch leaves strongly squarrose at acumen, hyaline cells with ringed pores at corners on the ventral surface		40 Sphagnum squarrosum
+	Plants dioicous, slender; perichaetial leaves similar to branch leaves in size; branch leaves slightly squarrose or erect at acumen, hyaline cells with unringed pores distantly set along commisures on the ventral surface		44 Sphagnum teres
36 (34)	Borders of stem leaves suddenly widened from the middle to the base		(37)
+	Borders of stem leaves narrow, evenly differentiated throughout		(45)
37 (36)	Stem leaves triangular, suddenly acute at the apex		(38)
+	Stem leaves short-ligulate or triangular-ligulate, rounded-obtuse at the apex		(41)
38 (37)	Stem leaves oblong-triangular to isosceles-triangular, upper hyaline cells with fibrils and pores		8 Sphagnum cuspidatum
+	Stem leaves short equilateral-triangular, hyaline cells without fibrils and pores		(39)
39 (38)	Stem leaves apiculate, not erose at the apex		11 Sphagnum fallax
+	Stem leaves broadly acute, slightly to distinctly erose across the apex		(40)
40 (39)	Stem leaves slightly erose at the apex; hyaline cells of branch leaves generally without pores		2 Sphagnum angustifolium
+	Stem leaves distinctly erose across the apex; hyaline cells of branch leaves with several large pores on both surfaces		35 Sphagnum recurvum
41 (37)	Branch leaves acuminate with a single-celled apex		33 Sphagnum pungifolium
+	Branch leaves generally blunt and truncate with a dentate apex		(42)
42 (41)	Hyaline cells of stem leaves densely fibrillose and porous		10 Sphagnum falcatulum
+	Hyaline cells of stem leaves without fibrils and pores, or rarely with traces of fibrils toward the leaf tips		(43)
43 (42)	Stem leaves triangular-ligulate, somewhat erose and dentate, with a very obscure sieve-like triangular area below the apex		25 Sphagnum obtusum
+	Stem leaves short ligulate, strongly lacerated, with a distinct sieve-like triangular area extending from the apex to the middle or below		(44)
44 (43)	Plants orange-brown or copper-colored when moist, reddish brown when dry; terminal buds not distinctive; hyaline cells of stem leaves undivided; branch leaves bordered by 1–2 rows of linear cells		19 Sphagnum lenense
+	Plants green to yellowish green when moist, light brown when dry; terminal buds very large; hyaline cells of stem leaves more or less once or twice divided toward the leaf apex; branch leaves bordered by 2–5 rows of linear cells		36 Sphagnum riparium
45 (36)	Stem and branch leaves clearly differentiated in size, especially in width; hyaline cells of stem leaves without pores; branch leaves ovate-lanceolate, gradually narrowed to a channelled apex		(46)
+	Stem and branch leaves similar in size; hyaline cells of stem leaves with pores; branch leaves oblong-elliptic, strongly concave with incurved upper margins, acute to broadly acute at the apex		(47)
46 (45)	Stem cortex in1–2 layers; stem leaves ½ as long as branch leaves, hyaline cells undivided; plants not shiny when dry		16 Sphagnum jensenii
+	Stem cortex in 2–3 layers; stem leaves nearly as long as branch leaves, hyaline cells 1-divided; plants shiny when dry		7 Sphagnum cuspidatulum
47 (45)	Stem cortex in 1 layer; hyaline cells of branch leaves with small, rounded, ringed pores along the commissures, green cells trapezoidal in cross section		20 Sphagnum luzonense
+	Stem cortex in 2–3 layers; hyaline cells of branch leaves with 2–4 small, rounded ringed pores at the corners, green cells triangular in cross section		43 Sphagnum tenellum