Family: Ophioglossaceae
Scott A. Milburn
Key to Wisconsin Sceptridium
- 1a.Pinnules of trophophore blade finely and deeply dissected, the ultimate segments sharply pointed S. dissectum
- 1b.Pinnules of trophophore blade entire to coarsely toothed 2
- 2a.Terminal pinnules (segments) longer and often less dissected than the lateral pinnules; blade segments often irregularly toothed or cut, bronze or green in winter 3
- 2b.Terminal pinnules (segments) similar to the lateral pinnules; blade finely toothed to coarsely dentate, green in winter 4
- 3a.Pinnules few, obliquely ovate, apex rounded; margins finely toothed; blades dull blue-green in summer, green in winter S. oneidense
- 3b.Pinnules (segments) numerous, linear to obliquely rhomboidal, apex acute; margins finely and coarsely toothed; blades shiny green in summer, bronze in winter S. dissectum
- 4a.Pinnules (segments), rounded, relatively uniform, nearly entire; blades leathery, shiny green or partly reddish in summer; plants large and robust S. multifidum
- 4b.Pinnae narrowly fan-shaped and well-separated, or more irregular in size and shape with apical margins usually toothed or cleft S. rugulosum
A genus of 10 to 20 species with many of the characteristics of Botrychium, including living underground for years dependent on mycorrhizal fungi, usually producing one above-ground sporophyte each year, often composed of a common stalk from which a photosynthetic trophophore and a fertile sporophyte arise near ground level. Unlike Botrychium, the trophophore may arise alone and the leaf blade is usually larger, broadly triangular, leathery, more horizontal, dark green or bronze, and evergreen, with a white (or tan) margin.
