Monographs Details: Riccia hegewaldiana Jovet-Ast
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Description:Species Description - Thalli in gregarious patches; lobes 5-8 mm long, 2-4 mm wide, slightly emarginate apically, 2-3 times forked, the basal dichotomies deep; dorsal side pale light brownish green when dry, margins wavy and crisped. Median groove very short. Epidermal cells granulose. Pores 40-55 µm diam., bounded by 5-6 hyaline, thin-walled cells. Ventral scales hyaline, large but not extending beyond lobe margins. Cross section of lobes 0.4-0.7 mm high, to 7 times as wide as high; dorsal side convex and acute laterally; flanks obliquely ascending, slightly concave and recurved apically; ventral edge nearly flat; air chambers in 2 layers, or in 1 layer and then high and narrow, partitions 1, rarely 2 cells wide; ventral tissue 1/3-1/4 of lobe height. Monoecious? Archegonial necks violet. Sporangia hardly bulging dorsally. Spores tetrahedral, red-brown with darker ridges, 65-79 µm diam.; wing 5-6(-12) µm wide, regular, thickened on margin, pores large; distal face with about 8 ill-delimited areoles across diam., with thick and ± sinuose ridges radiating from pole to equator; proximal face with numerous, small, often incomplete areoles, with slender ridges and tubercles, triradiate scar weak.

Discussion:Riccia hegewaldiana is related to R. frostii and R. paraguayensis by its spore ornamentation pattern, but the thallus lobes are thicker than those of R. paraguayensis and the thalli do not form rosettes. From R. frostii the species differs, moreover, by its wider, dorsally pale green lobes with scales reaching lobe margins, and the larger spores.
Distribution:Peru South America| La Libertad Peru South America|