Monographs Details: Riccia ianthina Jovet-Ast
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Family:Ricciaceae
Description:Species Description - Thalli in gregarious patches; lobes 2-3 times forked, 6 mm long, 2 mm wide, rounded or truncate apically, 1.5-1.7 mm wide beyond the apical dichotomy; dorsal side bright green when moist, pale bluish green when dry, violaceous in older parts and on both sides of median groove, with light green strips on margins; flanks inflexed, violet; ventral side violet. Median groove narrow and deep apically, flattened toward base. Epidermal cells slightly concave, sometimes with median mamilla, persistent in the groove and on the flanks of the groove. Ventral scales large, not extending beyond lobe margins, pink or pink-violet, margins entire, with 2 rows of hyaline cells. Cross section of lobes 1.5-3 times as wide as high; dorsal edge acute laterally; flanks obliquely ascending; ventral edge convex; dorsal tissue 1/3-1/2 of lobe height, in 6-9 layers, cells with thin, pitted, longitudinal strips. Monoecious. Necks of antheridia and archegonia hardly protruding. Spores nearly spherical, 96-108 µm diam., red-brown or tinged with pink-violet, wingless; distal face with (12-) 16 well-delimited areoles across diam., each 6-8 Jim diam., smaller near pole than at periphery, with conspicuous tubercles; proximal face with similar ornamentation, triradiate scar indistinct.

Discussion:Riccia ianthina is related to R. iodocheila and R. violacea. However, in R. iodocheila and R. violacea the lobe margins, flanks, and, in R. iodocheila, lobe apex have papillae and the margins of the scales are provided with violaceous papillae and short hyaline setae. Moreover, in the latter 2 species tubercles are lacking at the comers of the areoles on the distal face of spores (present in R. ianthina).
Distribution:Galápagos Islands Ecuador South America|