STEMS: monomorphic, not readily fragmenting when dry, the branch tips appearing straight when dry, prostrate, forming small, low, loose or dense cushionlike mats. RHIZOPHORES: produced throughout. LEAVES: slightly dimorphic, 2.5–5.0 mm long, (adaxial leaves sometimes slightly shorter than the abaxial leaves, linear to narrowly lanceolate, green to dark green when hydrated (adaxial leaves often persistently tan to brownish-tinged), the base decurrent (similar in color to the stem) and somewhat oblique, the tip with a straight or somewhat curved white seta 0.4–1.9 mm long (often breaking off with age), the margins ciliate. STROBILI: 1–3 mm long, the sporophylls broadly lanceolate to ovate, narrowed to an acute tip with or without a seta, the margins entirely ciliate or denticulate distally. MEGASPORES: usually relatively coarsely rugose-reticulate, orange. NOTES: 3 vars.; w U.S. e to ND and TX, AK; Can. REFERENCES: Yatskievych, G. and M. D. Windham. 2009. Vascular Plants of Arizona: Selaginellaceae. CANOTIA 5 (1): 39–48.