STEMS: monomorphic or slightly dimorphic, the main stem prostrate, with short ascending branches, readily fragmenting when dry, the branch tips appearing straight when dry, forming small, low, dense cushion-like mats. RHIZOPHORES: produced throughout. LEAVES: monomorphic, 2.0–4.5 mm long, linear to narrowly oblong-lanceolate, green to dark green when hydrated, the base decurrent (similar in color to the stem) and more or less symmetrically narrowed, the tip narrowly pointed, sometimes with a straight or somewhat curved white seta 0.2–0.5 mm long (often breaking off with age), this denticulate, the margins relatively short-ciliate, sometimes grading to denticulate distally. STROBILI: 4–15 mm long, the sporophylls broadly lanceolate to ovate-deltate, narrowed to an acute tip with a short seta, the margins denticulate, sometimes short-ciliate proximally MEGASPORES: smooth to finely rugose-reticulate, orange. NOTES: Rock outcrops, ledges, and cliffs, on limestone: Coconino, Mohave cos. (Fig. 1D); 600–1300 m (2000–4300 ft); nw AZ and adjacent s NV and e CA. REFERENCES: Yatskievych, G. and M. D. Windham. 2009. Vascular Plants of Arizona: Selaginellaceae. CANOTIA 5 (1): 39–48.