Monographs Details: Riccia ridleyi A.Gepp
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Scientific Name:Riccia ridleyi A.Gepp
Synonyms:Riccia bistriata A.Evans
Description:Species Description - Thalli in gregarious patches; lobes 4.5 mm long, 1.3-2 mm wide, once forked, the dichotomy reaching half of lobe length, rounded apically; dorsal side grayish green with narrow, acute, violet margin of large, hyaline or violet cells with thickened walls; flanks pink or pink-violaceous; ventral side pale green, sometimes pink-violaceous. Median groove deep. Epidermal cells disintegrating except in groove, pyriform, upper wall convex. Ventral scales imbricate, rounded apically, reaching or extending beyond lobe margins. Cross section of lobes 2-4 times as wide as high; dorsal edge rounded laterally; flanks oblique, with 1-2 hyaline or pink cells apically; ventral edge convex; dorsal tissue 1/3 of lobe height, in 5-7 cell layers, cell walls with 2 thickened, longitudinal strips. Dioecious? Spores tetrahedral, 98-120 µm diam., red-brown or red-violet; wing incomplete, narrow, light brown; distal face with 10-15 incomplete areoles across diam., distinguished by thick, irregular dark red or nearly black tubercles; proximal face with short ridges and ± large tubercles of varying size, forming a network of incomplete areoles, triradiate scar weak or indistinct.

Discussion:For differences with the allied R. weinionis and R. vitalii, see under R. vitalii.
Distribution:Brazil South America| Cusco Peru South America| Falcón Venezuela South America| Pernambuco Brazil South America|