Plants minute, rarely more than 10 cm. Stems 0.3–3 cm, covered by leaves or leaf bases. Leaves dimorphic. Sterile leaves ± coiled and spreading, very numerous, somewhat flattened, 1–5 cm × 0.2–0.3 mm. Fertile leaves upright, 1–12 cm; petioles long, straight, filiform; fertile blades apical, short, folded, 2–8 × 1–3 mm, segments 3–8 pairs, with multicellular hairs along margins. Gametophyte an algalike, branching filament. 2n = 206.
Habitat: Very local in bogs, wet, sandy depressions, crevices of ledges along shores.
St. Pierre and Miquelon, N.B., Nfld. and Labr. (Nfld.), N.S., Del., N.J., N.Y.
One of the most famous plants of the New Jersey Pine Barrens, this peculiar little plant has attracted much interest (W. H. Wagner Jr. 1963). It is abundant in southern Newfoundland. Plants from eastern Canada are shorter and denser than those from New Jersey. The same or a closely related species has been reported from Peru (R. G. Stolze 1987).