Plants terrestrial. Roots occasionally branching laterally, yellowish to black, 0.5–2 mm diam., smooth or with corky ridges, not proliferous. Stems upright, forming caudex to 5 mm thick; gemmae absent or minute, spheric. Trophophores ascending to perpendicular to stem, sessile or stalked; blades linear, oblong, or deltate, simple to 5-pinnate, 4–25 × 1–35 cm. Pinnae (reduced to segments in many species) spreading to ascending, fan-shaped to lanceolate to linear; margins entire to dentate to lacerate, apex rounded or acute; veins free, arranged like ribs of fan or pinnate. Sporophores normally 1 per leaf, 1–3-pinnate, long-stalked, borne at ground level to high on common stalk. Sporangial clusters with sporangia sessile to short-stalked, almost completely exposed, borne in 2 rows on pinnate (except in very small plants) sporophore branches. Gametophytes broadly ovate, unbranched, 1–3 × 1–10 mm. x =44, 45, 92.

Distribution

Nearly worldwide.

Discussion

The greatest diversity in Botrychium is at high latitudes and high elevations, mostly in disturbed meadows and woods. Extensive field and laboratory research has revealed unexpected diversity in North America, especially in subg. Botrychium. For accurate identification, a substantial number of carefully spread and pressed leaves are usually needed because of the large amount of variation found in most species. Taking many samples will have little effect on the population as long as the underground shoots and roots are left intact. Approximately a dozen sterile hybrid combinations have been encountered, but they are very infrequent.

The range maps south of Canada reflect mostly local occurrences at high elevations (1000–3700 m) in the mountains. The ranges for many of the species are probably more extensive and continuous than indicated by our present knowledge.

Species 50–60 (30 in the flora).

Selected References

Clausen, R.T. 1938. A monograph of the Ophioglossaceae. Mem. Torrey Bot. Club. 19(2): 1--177.

Wagner, W.H. Jr. and F.S. Wagner. 1983. Genus communities as a systematic tool in the study of New World Botrychium (Ophioglossaceae). Taxon 32: 51--63.

Wagner, W.H. Jr. and F.S. Wagner. 1990. Moonworts (Botrychium subg. Botrychium) of the upper Great Lakes region. Contr. Univ. Michigan Herb. 17: 313--325.

Wagner, F. S. 1993. Chromosomes of North American grapeferns and moonworts (Ophioglossaceae: Botrychium). Contr. Univ. Michigan Herb. 19: 83--92.

Lower Taxa

Botrychium subg. Botrychium, Botrychium subg. Osmundopteris, Botrychium subg. Sceptridium

Key

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).	Botrychium 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).	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium oneidense
7	Pinnules obliquely trowel-shaped or linear, margins denticulate to lacerate or coarsely cut, apex acute; trophophore blades bronze in winter if exposed.	Botrychium dissectum
8	Segments of blades rounded, nearly entire, plane; texture leathery; n North America.	Botrychium multifidum
8	Segments of blades angular, ± dentate, somewhat channeled and concave abaxially; texture semiherbaceous; Great Lakes and St. Lawrence Seaway region.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium lunaria
19	Pinnae strongly ascending; margins conspicuously dentate-lacerate.	Botrychium 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.	Botrychium 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.	Botrychium pallidum
22	Blades narrowly oblong, firm to herbaceous; pinnae nearly spheric to fan-shaped; margins shallowly crenate; proximal sporophore branches 1-pinnate.	Botrychium 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.	Botrychium spathulatum
23	Trophophore replaced by sporophore, yielding 2 sporophores.	Botrychium paradoxum
23	Trophophore present, fully distinct from sporophore.	> 24
24	Trophophore blades deltate; sporophores divided proximally into several equally long branches.	Botrychium 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.	Botrychium 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.	Botrychium 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.	Botrychium matricariifolium
28	Pinnae oblanceolate to linear-lanceolate, acuminate, entire to shallowly lobed.	Botrychium acuminatum
29	Pinnae acute, oblanceolate to narrowly spatulate, rarely more than 2-lobed; pinnae well separated.	Botrychium 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.	Botrychium 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.	Botrychium pseudopinnatum
31	Pinnae ± ascending to ± horizontal, usually approximate to somewhat remote; trophophore blades papery, shiny; nw North America.	Botrychium pinnatum