TYPE: VENEZUELA. Bolivar: Ptari-te- pui, between "Cave Rock" and base of sandstone bluff, 2285-2405 m, 30 Oct 1944, J. A. Steyermark 59563 (HOLOTYPE: NY; ISOTYPES: BM-n.v., F-n.v., MO, PMA, US- n.v.).
A S. microdonta A. C. Smith foliis idioblastis utrinque provisis, foliis lateralibus plerumque cordatis vel deltato-ovatis vel late ovatis, foliisque intermediis cordatis diversa.
Etymology-Gr., cardio, heart, and phyllus, leaved; referring to the heart-shaped leaves, especially the median ones.
Selaginella cardiophylla belongs to subg. Stachygynandrum (P. Beauv.) Baker. It is noteworthy because of its large, basal spo- rophylls, which mostly bear megasporangia. This characteristic is mostly restricted to species of series Articulatae Spring; however, S. cardiophylla lacks most of the important distinguishing characters of this se- ries (e.g., articulate stems, echinate microspores, dorsal rhizophores, and the particular microsporangium type described by Somers, 1982). Thus, I do not believe that it should be placed in series Articulatae
The type collection of S. cardiophylla was cited by Alston et al. (1981) as S. microdonta A. C. Smith. I have examined several specimens of S. microdonta, including the holotype (Tate 509, NY), and have concluded that S. microdonta and S. cardio- phylla are different species. Selaginella cardiophylla differs from S. microdonta by having leaves with conspicuous (vs without) idioblasts, hyaline (vs chlorophyllous) margins; cordiform (vs ovate-lanceolate to ovate-cordiform) median leaves, cordate to infrequently rounded (vs oblique, with an outer subventricose auricle) median leaf base; mostly cordiform to deltate-ovate, or broadly ovate (vs orbicular, broadly ovate, ovate-elliptic, or ovate-oblong) lateral leaves; stem 2- or 3- (vs mostly 1 -)branched, and sporophyll surfaces with (vs without) idioblasts. Additionally, S. cardiophylla is known only from the Ptari-tepui in the Estado Bolivar, whereas S. microdonta has been found only on the tepuis of T. F. Ama- zonas, Venezuela.