OregonFlora: Botrychium paradoxum vs. Botrychium virginianum

	Botrychium paradoxum	Botrypus virginianus (synonym of Botrychium virginianum)
	paradox moonwort	rattlesnake-fern
Habit	Plants 7–15 cm tall above ground, dull green, glaucous in life.	Plants to 40 cm tall.
Spores	36– 43 μm.
Common stalks	well developed; greater than 2 cm, green.
Trophophores	appearing absent, converted entirely to a second sporophore without any trace of lamina.	3–4 -pinnate; to 30 × 30 cm; grass-green; neither glaucous nor glossy; pinnae to 12 pairs, spreading to slightly ascending; flat, slightly overlapping or well spaced; lobes lanceolate; tips acute; margins entire to serrate.
Sporophores	stiffly erect, slightly unequal in length, nearly sessile or with stalks up to 50% the entire sporophore length at spore release; branches much reduced and usually less than 5 mm long, often appearing absent.	stalk (0.5)1–2 times as long as trophophore at spore release.
2n	=180 (allotetraploid, derived; in part; from an undescribed diploid that resembles B. montanum).	=184.

	Botrychium paradoxum	Botrypus virginianus
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Mesic subalpine meadows, usually among grasses, sedges, and low forbs, but occasionally in denser herbaceous cover or under trees. 1500–1800 m. BW. CA, ID, WA; northwestern North America. Native. Botrychium paradoxum is unique in having two sporophores and no trophophore. However, other species occasionally produce forms with the trophophore partly or completely transformed into a second sporophore. These usually have sporophores of clearly unequal lengths or with elongate branches, and often occur as isolated individuals among normal, trophophorebearing plants. As currently circumscribed, B. paradoxum contains two distinct genotypes.	Moist soil and duff in coniferous or deciduous forest or under shrubs, often near streams or on margins of wetlands and fens, rarely on meadow margins. 100–1700 m. BW, Casc, ECas. CA, ID, NV, WA; throughout North America, South America; Eurasia. Native. Very small plants in exposed habitats could be confused with Botrychium lanceolatum, from which it can be distinguished by the thinner, herbaceous texture, prominent midribs, sharply acute pinnae lobes, and longer sporophore stalk.
Source	Flora of Oregon, volume 1, page 91 Ben Legler	Flora of Oregon, volume 1, page 93 Ben Legler
Sibling taxa	B. ascendens, B. crenulatum, B. hesperium, B. lanceolatum, B. lineare, B. lunaria, B. minganense, B. montanum, B. pedunculosum, B. pinnatum, B. pumicola, B. simplex	B. virginianus
Synonyms		Botrychium virginianum
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Botrypus virginianus

(synonym of Botrychium virginianum)

paradox moonwort

rattlesnake-fern

Habit

Plants 7–15 cm tall above ground, dull green, glaucous in life.

Plants to 40 cm tall.

Spores

36– 43 μm.

Common stalks

well developed; greater than 2 cm, green.

Trophophores

appearing absent, converted entirely to a second sporophore without any trace of lamina.

3–4 -pinnate; to 30 × 30 cm; grass-green; neither glaucous nor glossy;

pinnae to 12 pairs, spreading to slightly ascending; flat, slightly overlapping or well spaced;

lobes lanceolate;

tips acute;

margins entire to serrate.

Sporophores

stiffly erect, slightly unequal in length, nearly sessile or with stalks up to 50% the entire sporophore length at spore release;

branches much reduced and usually less than 5 mm long, often appearing absent.

stalk (0.5)1–2 times as long as trophophore at spore release.

=180 (allotetraploid, derived; in part; from an undescribed diploid that resembles B. montanum).

=184.

Botrypus virginianus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Mesic subalpine meadows, usually among grasses, sedges, and low forbs, but occasionally in denser herbaceous cover or under trees. 1500–1800 m. BW. CA, ID, WA; northwestern North America. Native.

Botrychium paradoxum is unique in having two sporophores and no trophophore. However, other species occasionally produce forms with the trophophore partly or completely transformed into a second sporophore. These usually have sporophores of clearly unequal lengths or with elongate branches, and often occur as isolated individuals among normal, trophophorebearing plants. As currently circumscribed, B. paradoxum contains two distinct genotypes.

Moist soil and duff in coniferous or deciduous forest or under shrubs, often near streams or on margins of wetlands and fens, rarely on meadow margins. 100–1700 m. BW, Casc, ECas. CA, ID, NV, WA; throughout North America, South America; Eurasia. Native.

Very small plants in exposed habitats could be confused with Botrychium lanceolatum, from which it can be distinguished by the thinner, herbaceous texture, prominent midribs, sharply acute pinnae lobes, and longer sporophore stalk.

Source

Flora of Oregon, volume 1, page 91
Ben Legler

Flora of Oregon, volume 1, page 93
Ben Legler

Sibling taxa