1	Leaf blades deltate, mostly 5--25 cm, commonly sterile, sporophores absent or misshapen; plants mostly over 12 cm; leaf sheaths open or closed.		(2)
+	Leaf blades mainly oblong to linear, mostly 2--4 cm, all fertile, sporophores always present; plants to 15 cm, mostly less than 10 cm; leaf sheaths closed (subg. Botrychium).		(9)
2 (1)	Trophophore blade thin, herbaceous; leaf sheaths open; sporophores, when present, arising from base of trophophore blade high on common stalk; leaves absent during winter (subg. Osmundopteris).		1 Botrychium virginianum
+	Trophophore blades herbaceous or thick-papery to leathery; leaf sheaths closed; sporophores, when present, arising near ground from basal portion of common stalk; leaves present during winter (subg. Sceptridium).		(3)
3 (2)	Trophophores prostrate, blades commonly 2 per plant; roots yellowish, to 30 per plant; sporophore stalks and midrib broadly flattened, fleshy; leaves dying in early spring, new leaves appearing in late fall (sect. Hiemobotrychium).		2 Botrychium lunarioides
+	Trophophores erect or ascending, blades commonly 1 per plant; roots blackish, to 15 per plant; sporophore stalks and midrib only slightly flattened, not fleshy; leaves appearing in late spring and lasting until following spring (subg. Sceptridium sect. Sceptridium).		(4)
4 (3)	Basal pinnae mostly long-stalked and remotely alternate; pinnule venation nearly like ribs of fan but with short midrib; blades dull gray-green.		5 Botrychium jenmanii
+	Basal pinnae short-stalked and mostly subopposite; pinnule venation pinnate, with strong midrib; blades bluish green or green to dark green.		(5)
5 (4)	Terminal pinnules larger than lateral pinnules; pinnae undivided except in proximal 1/2--3/4.		(6)
+	Terminal pinnules similar to or only slightly larger than lateral pinnules; pinnae divided to tip.		(8)
6 (5)	Trophophore blades usually 2--3-pinnate, terminal pinnae elongate and nearly parallel-sided; leaves mostly remaining green during winter.		3 Botrychium biternatum
+	Trophophore blades usually 2--4-pinnate, pinnules trowel-shaped or ovate (rarely linear), apex rounded to acute; leaves green or bronze during winter.		(7)
7 (6)	Pinnules obliquely ovate, margins finely denticulate to crenulate, apex rounded to acute; trophophore blades green in winter.		7 Botrychium oneidense
+	Pinnules obliquely trowel-shaped or linear, margins denticulate to lacerate or coarsely cut, apex acute; trophophore blades bronze in winter if exposed.		4 Botrychium dissectum
8 (5)	Segments of blades rounded, nearly entire, plane; texture leathery; n North America.		6 Botrychium multifidum
+	Segments of blades angular, ± dentate, somewhat channeled and concave abaxially; texture semiherbaceous; Great Lakes and St. Lawrence Seaway region.		8 Botrychium rugulosum
9 (1)	Trophophores linear to linear-oblong, simple to lobed, lobes rounded to square and angular, stalks usually 1/3--2/3 length of trophophore; plants in deep shade under shrubs and trees.		(10)
+	Trophophores linear to deltate (narrowly oblong in Botrychium minganese), pinnate, rarely simple, lobes, if present, of various shapes, stalk usually less than 1/4 length of trophophore; plants usually in exposed sites.		(12)
10 (9)	Segments rounded; plants herbaceous.		29 Botrychium simplex
+	Segments angular; plants succulent.		(11)
11 (10)	Surfaces shiny yellow-green (alive); blade apex undissected or with 2--3 lobes, cutting fairly regular; trophophore stalks very succulent; Great Lakes region.		21 Botrychium mormo
+	Surfaces dull gray-green (alive); blade apex dissected with 3--5 lobes or projections, cutting somewhat irregular; trophophore stalks somewhat succulent; far w North American mountains.		20 Botrychium montanum
12 (9)	Distance between 1st and 2d pinna pairs greater than that between 2d and 3d pairs; segments asymmetric, enlarged on acroscopic side.		(13)
+	Distance between 1st and 2d pinna pairs same or slightly more than between 2d and 3d pairs; segments asymmetric to symmetric.		(14)
13 (12)	Apex of blade undivided or coarsely divided; pinnae ovate--fan-shaped, margins shallowly sinuate; small leaves frequently simple or nearly so; large mature blades subternate to ternate; sporophores 1-pinnate; nearly circumboreal.		29 Botrychium simplex
+	Apex of blade always finely divided; pinnae fan-shaped to narrowly spatulate, margins crenate to dentate or jagged; small leaves always deeply lobed or pinnate; large mature blades oblong-linear; sporophores 2--3-pinnate; w Minnesota prairie.		14 Botrychium gallicomontanum
14 (12)	Trophophores present; basal pinnae or segments with venation like ribs of fan, midrib absent; basal pinnae fan-shaped to spatulate.		(15)
+	Trophophores present or replaced by sporophore; if present, basal pinnae or segment venation pinnate, midrib present, oblanceolate to linear to lanceolate to ovate.		(23)
15 (14)	Trophophore blades ovate to deltate.		(16)
+	Trophophore blades oblong to oblong-lanceolate.		(17)
16 (15)	Sporophores 3--5 times length of trophophores, arising at or just above leaf sheath; blades bright green, pinnae remote or approximate, fan-shaped, papery; widespread, w North America.		29 Botrychium simplex
+	Sporophores 1--1.5 times length of trophophores, arising high on common stalk; blades dull whitish green, pinnae overlapping, cuneate, leathery; sw Oregon.		28 Botrychium pumicola
17 (15)	Basal pinnae broadly fan-shaped.		(18)
+	Basal pinnae narrowly fan-shaped, or cuneate to lanceolate or linear.		(19)
18 (17)	Plants herbaceous; trophophores on most plants less than 4 × 1.5 cm; pinnae 2--5 pairs, well separated; margins commonly crenate to dentate; sporophores 1.3--3 times length of trophophore; damp sites; w North America.		12 Botrychium crenulatum
+	Plants fleshy; trophophores on most plants more than 5 × 2 cm; pinnae 4--9 pairs, approximate to overlapping; margins usually entire to undulate, rarely dentate; sporophores 0.8--2 times length of trophophore; dry sites; widespread.		17 Botrychium lunaria
19 (17)	Pinnae strongly ascending; margins conspicuously dentate-lacerate.		10 Botrychium ascendens
+	Pinnae spreading or only moderately ascending; outer margins entire to crenate or rarely dentate.		(20)
20 (19)	Trophophores ± folded longitudinally when alive, usually to 4 × 1 cm; pinnae to 5 pairs, most proximal pinnae 2-lobed.		(21)
+	Trophophores flat or folded only at base when alive, usually to 10 × 2.5 cm; pinnae to 10 pairs, basal pinnae unlobed or if lobed, not usually 2-cleft.		(22)
21 (20)	Blades very fleshy; sporophores usually less than 1.5 times length of trophophores; pinnae mostly linear; basal pinna lobes usually ± equal; appearing in spring.		11 Botrychium campestre
+	Blades herbaceous; sporophores usually 1.5--4 times length of trophophores; pinnae asymmetrically fan-shaped; basal pinna lobes unequal; appearing in late spring.		22 Botrychium pallidum
22 (20)	Blades narrowly oblong, firm to herbaceous; pinnae nearly spheric to fan-shaped; margins shallowly crenate; proximal sporophore branches 1-pinnate.		19 Botrychium minganense
+	Blades narrowly deltate, leathery; pinnae spatulate to linear-spatulate; margins entire to very coarsely and irregularly dentate; most proximal sporophore branches usually 2-pinnate.		30 Botrychium spathulatum
23 (14)	Trophophore replaced by sporophore, yielding 2 sporophores.		23 Botrychium paradoxum
+	Trophophore present, fully distinct from sporophore.		(24)
24 (23)	Trophophore blades deltate; sporophores divided proximally into several equally long branches.		16 Botrychium lanceolatum
+	Trophophore blades ovate to oblong (nearly deltate in Botrychium hesperium, deltate-oblong in B. pinnatum); sporophores with single midrib or 1 dominant midrib and 2 smaller ribs.		(25)
25 (24)	Trophophore stalk long, equal to length of trophophore rachis; blade mostly ovate-oblong to deltate-oblong; basal pinnae ovate-rhombic; nw North America.		24 Botrychium pedunculosum
+	Trophophore stalk short to nearly absent, to 1/4 length of trophophore rachis; blade mainly oblong-lanceolate to triangular; most basal pinnae elongate, oblanceolate to oblong to linear or linear-lanceolate.		(26)
26 (25)	Large trophophore blades nearly deltate, basal pinna pair elongate; pinnae distal to basal pair approximate to overlapping; segments and lobes rounded at apex.		15 Botrychium hesperium
+	Large trophophore blades mostly oblong-deltate to ovate-oblong; basal pinna pair not elongate; pinnae distal to basal pair remote to approximate; segments and lobes truncate, rounded, or acute at apex.		(27)
27 (26)	Sporophores long, 1--3 times length of trophophore; blades dull, blue to green.		(28)
+	Sporophores short, only 1--2 times length of trophophore; blades shiny, bright green.		(29)
28 (27)	Pinnae ovate to lanceolate, blunt, shallowly to deeply lobed.		18 Botrychium matricariifolium
+	Pinnae oblanceolate to linear-lanceolate, acuminate, entire to shallowly lobed.		9 Botrychium acuminatum
29 (27)	Pinnae acute, oblanceolate to narrowly spatulate, rarely more than 2-lobed; pinnae well separated.		13 Botrychium echo
+	Pinnae mostly with rounded apex, ovate to broadly spatulate, to 6-lobed; pinnae approximate to overlapping.		(30)
30 (29)	Pinnae of mature trophophores nearly as wide as long, with slightly pointed tips, costa rudimentary, veins otherwise ± like ribs of fan; basal pinnae with only shallow, narrow sinuses and 1--3 lobes.		26 Botrychium boreale
+	Pinnae of mature trophophores considerably longer than wide, mostly with blunt tips, veins mainly pinnate; basal pinnae with deep, ± wide sinuses and 3--8 lobes.		(31)
31 (30)	Pinnae ascending, usually somewhat overlapping; trophophore blades leathery, somewhat shiny; Lake Superior region.		27 Botrychium pseudopinnatum
+	Pinnae ± ascending to ± horizontal, usually approximate to somewhat remote; trophophore blades papery, shiny; nw North America.		25 Botrychium pinnatum