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 |
1. 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. 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). | B. virginianum |
2. 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. 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). | B. lunarioides |
3. 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. Basal pinnae mostly long-stalked and remotely alternate; pinnule venation nearly like ribs of fan but with short midrib; blades dull gray-green. | B. jenmanii |
4. Basal pinnae short-stalked and mostly subopposite; pinnule venation pinnate, with strong midrib; blades bluish green or green to dark green. | → 5 |
5. Terminal pinnules larger than lateral pinnules; pinnae undivided except in proximal 1/2–3/4. | → 6 |
5. Terminal pinnules similar to or only slightly larger than lateral pinnules; pinnae divided to tip. | → 8 |
6. Trophophore blades usually 2–3-pinnate, terminal pinnae elongate and nearly parallel-sided; leaves mostly remaining green during winter. | B. biternatum |
6. 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. Pinnules obliquely ovate, margins finely denticulate to crenulate, apex rounded to acute; trophophore blades green in winter. | B. oneidense |
7. Pinnules obliquely trowel-shaped or linear, margins denticulate to lacerate or coarsely cut, apex acute; trophophore blades bronze in winter if exposed. | B. dissectum |
8. Segments of blades rounded, nearly entire, plane; texture leathery; n North America. | B. multifidum |
8. Segments of blades angular, ± dentate, somewhat channeled and concave abaxially; texture semiherbaceous; Great Lakes and St. Lawrence Seaway region. | B. rugulosum |
9. 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 |
9. 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. Segments rounded; plants herbaceous. | B. simplex |
10. Segments angular; plants succulent. | → 11 |
11. Surfaces shiny yellow-green (alive); blade apex undissected or with 2–3 lobes, cutting fairly regular; trophophore stalks very succulent; Great Lakes region. | B. mormo |
11. 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. | B. montanum |
12. Distance between 1st and 2d pinna pairs greater than that between 2d and 3d pairs; segments asymmetric, enlarged on acroscopic side. | → 13 |
12. Distance between 1st and 2d pinna pairs same or slightly more than between 2d and 3d pairs; segments asymmetric to symmetric. | → 14 |
13. 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. | B. simplex |
13. 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. | B. gallicomontanum |
14. Trophophores present; basal pinnae or segments with venation like ribs of fan, midrib absent; basal pinnae fan-shaped to spatulate. | → 15 |
14. 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. Trophophore blades ovate to deltate. | → 16 |
15. Trophophore blades oblong to oblong-lanceolate. | → 17 |
16. 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. | B. simplex |
16. Sporophores 1–1.5 times length of trophophores, arising high on common stalk; blades dull whitish green, pinnae overlapping, cuneate, leathery; sw Oregon. | B. pumicola |
17. Basal pinnae broadly fan-shaped. | → 18 |
17. Basal pinnae narrowly fan-shaped, or cuneate to lanceolate or linear. | → 19 |
18. 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. | B. crenulatum |
18. 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. | B. lunaria |
19. Pinnae strongly ascending; margins conspicuously dentate-lacerate. | B. ascendens |
19. Pinnae spreading or only moderately ascending; outer margins entire to crenate or rarely dentate. | → 20 |
20. Trophophores ± folded longitudinally when alive, usually to 4 × 1 cm; pinnae to 5 pairs, most proximal pinnae 2-lobed. | → 21 |
20. 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. Blades very fleshy; sporophores usually less than 1.5 times length of trophophores; pinnae mostly linear; basal pinna lobes usually ± equal; appearing in spring. | B. campestre |
21. Blades herbaceous; sporophores usually 1.5–4 times length of trophophores; pinnae asymmetrically fan-shaped; basal pinna lobes unequal; appearing in late spring. | B. pallidum |
22. Blades narrowly oblong, firm to herbaceous; pinnae nearly spheric to fan-shaped; margins shallowly crenate; proximal sporophore branches 1-pinnate. | B. minganense |
22. Blades narrowly deltate, leathery; pinnae spatulate to linear-spatulate; margins entire to very coarsely and irregularly dentate; most proximal sporophore branches usually 2-pinnate. | B. spathulatum |
23. Trophophore replaced by sporophore, yielding 2 sporophores. | B. paradoxum |
23. Trophophore present, fully distinct from sporophore. | → 24 |
24. Trophophore blades deltate; sporophores divided proximally into several equally long branches. | B. lanceolatum |
24. 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. Trophophore stalk long, equal to length of trophophore rachis; blade mostly ovate-oblong to deltate-oblong; basal pinnae ovate-rhombic; nw North America. | B. pedunculosum |
25. 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. Large trophophore blades nearly deltate, basal pinna pair elongate; pinnae distal to basal pair approximate to overlapping; segments and lobes rounded at apex. | B. hesperium |
26. 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. Sporophores long, 1–3 times length of trophophore; blades dull, blue to green. | → 28 |
27. Sporophores short, only 1–2 times length of trophophore; blades shiny, bright green. | → 29 |
28. Pinnae ovate to lanceolate, blunt, shallowly to deeply lobed. | B. matricariifolium |
28. Pinnae oblanceolate to linear-lanceolate, acuminate, entire to shallowly lobed. | B. acuminatum |
29. Pinnae acute, oblanceolate to narrowly spatulate, rarely more than 2-lobed; pinnae well separated. | B. echo |
29. Pinnae mostly with rounded apex, ovate to broadly spatulate, to 6-lobed; pinnae approximate to overlapping. | → 30 |
30. 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. | B. boreale |
30. 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. Pinnae ascending, usually somewhat overlapping; trophophore blades leathery, somewhat shiny; Lake Superior region. | B. pseudopinnatum |
31. Pinnae ± ascending to ± horizontal, usually approximate to somewhat remote; trophophore blades papery, shiny; nw North America. | B. pinnatum |