Selaginella trygonoides Valdespino. A Section of upper surface of stem B Upper surface of median leaf; note submarginal stomata (a) on inner half of the lamina C Close-up of inner margin of median leaf, upper surface; note submarginal stomata (a) D Close-up of median leaf upper surface; note papillae on cell lumen E Upper surface of median leaf; note submarginal stomata on inner half of the lamina F Close-up of base, portion of inner margin and inner half of lamina (note stomata), and portion of outer margin and outer half of lamina of median leaf, upper surface G Upper surface of lateral leaf and portion of median leaves, upper surface H Close-up of distal portion and apex of lateral leaf, upper surface. A–H taken from the holotype, Almeida et al. 1994 (PMA).