Monographs Details: Riccia australis Steph.
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Scientific Name:Riccia australis Steph.
Description:Species Description - Thalli forming partial rosettes or gregarious mats; lobes 2-3 times forked, 6-8 mm long, 1-2 mm wide, rounded, thick, and weakly emarginate apically, thin below; dorsal side light green or grayish, sometimes with violet strip or violet venules on margins, and violaceous spots above sporangia. Median groove shallow, distinct only apically. Epidermal cells rounded or pyriform. Ventral scales small, hyaline, violet, or violaceous. Cross section of lobes 3 times as wide as high near apex of lobes, 5-6 times as wide as high below, of 10-15 cell layers; dorsal edge rounded laterally or acute, with thin wings, often tinged with violet; flanks obliquely ascending; ventral edge slightly convex; dorsal tissue in 2 layers. Dioecious. Spores tetrahedral, (84-)96-120 µm diam., light yellow-brown with brown ornamentation; wing 3-7 µm wide, irregular, papillose distal face with 8-9(-10) areoles across diam., limited by low and narrow ridges with large tubercles; proximal face similarly ornamented, with smaller tubercles, triradiate scar weak.

Discussion:Riccia australis is allied to R. grandis. However, the thalli form complete rosettes in R. grandis, with lobes to 4 mm wide, and the spores are smaller, less than 95 µm in diam.
Distribution:São Paulo Brazil South America| Pernambuco Brazil South America| Rio Grande do Sul Brazil South America| Paraná Brazil South America| Misiones Argentina South America| Loreto Peru South America| Pichincha Ecuador South America| Canelones Uruguay South America| San José Uruguay South America| Falcón Venezuela South America|