Selaginella falcata (P. Beauv.) Spring

Valdespino, Ivan A., 2015, Novelties in Selaginella (Selaginellaceae - Lycopodiophyta), with emphasis on Brazilian species, PhytoKeys 57, pp. 93-133 : 109

Selaginella falcata (P. Beauv.) Spring

Selaginella falcata (P. Beauv.) Spring, Bull. Acad. Roy. Sci. Bruxelles 10: 225. 1843. - Stachygynandrum falcatum P. Beauv. Mag. Encycl. 9e Année, 5: 483. 1804. - Type. French Guiana. [without date or precise locality], [A.?] Chastelein s.n. (OXF-n.v.).

Additional specimens examined.

BRAZIL. Amapá: Rio Pontanari, 03°45'N, 51°42'W, 31 Jul 1960, Irwin et al. 47271 (NY, UC); 1956, Bastos 70 [2070] (RB), Bastos 2070 (RB).

Discussion.

In Alston et al (1981), Selaginella falcata was documented only in French Guiana; here its range is extended to include Brazil. This is a very distinct species because of its creeping to prostrate habit, ovate-deltate or deltate median leaves, large oblong, lateral leaves each 4-7.5 mm long, and main stem width (including lateral leaves) 8.0-15 mm. In Brazil, Selaginella falcata may be confused with Selaginella mendocae Hieron., because of their similar habit and stem width (including lateral leaves). However, the former differs from the latter by ovate-deltate or deltate (vs. orbiculate) median leaves, with both halves equal in width (vs. outer halves wider than inner ones), and leaf bases cordate (vs. bases oblique or inner ones truncate and outer bases lobed). Another species with similar median leaves as those of Selaginella falcata is Selaginella kochii . These two taxa are part of the Selaginella falcata group and can be separated by the characters provided in the key under Selaginella cabrerensis .