Monographs Details: Riccia limicola Jovet-Ast
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Family:Ricciaceae
Description:Species Description - Thallus lobes 0.3-0.5(-0.7) mm wide, rounded or emarginate apically; 2-3 times forked, basal dichotomy deep, 6-10 mm long, apical shorter, l-2.5(-4) mm long; dorsal side grayish green or light green and shiny. Median groove deep on the terminal branch, evanescent elsewhere. Pores 25 µm diam., bounded by 4 thin-walled cells. Ventral scales not seen. Cross section of lobes 2-3 times as wide as high near apex of lobes to 5 times wider at base; dorsal edge rounded laterally; flanks obliquely ascending; ventral edge convex; air chambers in 1-2 layers; ventral tissue in about 5 layers. Monoecious. Sporangia bulging ventrally. Spores tetrahedral to spherical, brown or red-brown, 80-92 µm diam.; wing light brown, 5-7 |im wide, granulose and wavy; distal face with (6-)7-8 areoles across diam., with thick ridges and triangular tubercles in the comers, and small tubercles on the ridges; proximal face with 12-17 areoles per facet, smaller than those of distal face, triradiate scar weak.

Discussion:Riccia limicola is related to R. stenophylla, but its lobes are less subdivided, with basal dichotomies deeper, more than 6 mm long. The areoles on the distal face of the spores are complete, with numerous tubercles on the ridges, but without central ornamentation inside. On the proximal face, the triradiate scar is less marked, and the ridges are more conspicuous.
Distribution:Galápagos Islands Ecuador South America|