Botrychium dissectum - (image 1 of 9)
Taxonomy
Family: Ophioglossaceae
Habitat
Woodlands, typically with Acer saccharum.
Associates
The most important association is with mycorrhizal fungi. The gametophyte is parasitic on a fungus which is in turn involved in a mycorrhiza with another plant.
Distribution
Nova Scotia and New Brunswick west to WI and southeast MN, south to FL and LA.
Morphology
Perennial, 10-30 cm or more. Leaves evergreen; blade attached well below the middle or nearly basal on a stalk 3-7 cm long, 3-4 times pinnate but highly variable, regularly or unequally dissected with the terminal segment and principle division somewhat elongate, sometimes finely divided throughout, with mostly 1-2 veinlets, slightly hairy at least in bud. Fertile spike 2-10 cm long, on a long stalk.
Because the leaves are highly variable, this has led to a great deal of taxonomic confusion. It has been suggested that B. oneidense (Gilbert) House is a separate species with leaves that stay green though the winter and with segments mostly obtuse or rounded, while B. dissectum has leaves that turn bronze and has segments mostly acute to acuminate. Taking this into account, both species may be present together in some of these images but I am skeptical. Less dissected forms of B. dissectum may resemble B. biternatum (Savigny) Underw, a southern species.
Notes
Spores produced early September to mid October
Wetland category: Facultative
This plant seems to thrive under sugar maples in areas that are occasionally mowed. Botrychium spp. are unique among ferns in that they have a vascular cambium that produces secondary xylem, although no secondary phloem is produced.
References
Gleason, Henry A.
and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States
and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
Swink, F. and G.
Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois
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© Michael Hough 2004 |