Monographs Details: Riccia squamata Nees
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Scientific Name:Riccia squamata Nees
Synonyms:Riccia subnigella Herzog
Description:Species Description - Thalli in gregarious patches; lobes 2-3 mm long, l.l-1.8(-2.3) mm wide, rounded apically; dorsal side light brown greenish, bordered by the black scales connate with the flanks, margins completely inflexed when dry; flanks dark red-violet; ventral side pale pink. Median groove shallow. Epidermal cells rounded or pyriform. Ventral scales black or red-violet, glossy, imbricate, with smaller marginal cells. Rhizoids all smooth. Cross section of lobes as wide as high apically to twice as wide as high below, and 2-2.5 times as wide as high basally; dorsal edge with a weak median groove; flanks ascending vertically; ventral edge convex; cells of dorsal tissue with thin longitudinal strips. Monoecious. Sporangia hardly bulging. Spores tetrahedral, 96-125 µm diam., brick red with darker ornamentation, wingless; distal face with 7-9(-11) areoles across diam., with thin ridges and large, anastomosed tubercles, the areoles sometimes replaced by folds near equator; proximal face nearly smooth, with few low reddish black tubercles and granules, triradiate scar weak, with narrow ridges.

Discussion:Riccia squamata is well characterized by spore shape, red color, and ornamentation. By its spore ornamentation R. squamata cannot be confused with any other neotropical Riccia species.
Distribution:Bahia Brazil South America| Piauí Brazil South America| Pernambuco Brazil South America| Minas Gerais Brazil South America| Curaçao South America| Zacatecas Mexico North America| Misiones Argentina South America| Brazil South America|