Key to Wisconsin Gymnocarpium
- 1a.Lowest pair of pinnae nearly as long as the terminal (main) division of the blade, the blade about as wide as long; rachis and midveins on underside of pinnae glabrous; blades thin and membranous G. dryopteris
- 1b.Blades ovate to narrowly lanceolate or elliptical, widest near middle, usually acute at apex; bulblets not produced; most or all veins ending in teeth (except many ending in notches in C. tenuis); tiny gland-tipped hairs lacking; plants often growing on forest soil or cliff faces 2
- 2a.Blades rank-smelling, glandular on the upper surface, especially on the midveins of the pinnae; lowest pair of pinnae diverging almost perpendicular to the rachis; second pair of pinnae usually with a short stalk G. robertianum
- 2b.Blades glabrous on upper surface; lowest pair of pinnae and lower pinnules curving upward toward blade apex; second pair of pinnae sessile G. jessoense
A cicumboreal genus, once considered part of Polypodium, Dryopteris, Phegopteris, or Thelypteris. Four diploid species occur in North America plus one allotetraploid species, as well as sterile or apogamous hybrids when pairs of species grow together.