Monographs Details: Riccia vitalii Jovet-Ast
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Scientific Name:Riccia vitalii Jovet-Ast
Description:Species Description - Thalli in gregarious patches, with fish odor; lobes deeply divided, 7 mm long, 1-2.3 mm wide, rounded apically; dorsal side pale or dark green; flanks and ventral side violet or pink-violet. Median groove shallow apically, vanishing below. Epidermis hyaline, disintegrating except in groove, cells convex. Ventral scales imbricate, violet or pink with hyaline marginal cells, extending beyond lobe margins. Cross section of lobes acute laterally with short, thin wings, of 1-3 hyaline or violaceous cells; flanks ascending, erect, or oblique; ventral edge convex; dorsal tissue 1/3-1/2 of lobe height, cell layer below epidermis with 2 thickened longitudinal strips on cell walls. Dioecious (sometimes monoecious?). Spores subspherical or subtetrahedral, 92-152 µm diam., dark red, or dark red-brown, or blackish, wingless; distal face with 69 ± complete areoles across diam., larger near pole than near equator, sometimes complete only near pole, with thick, irregular, rugulose ridges and irregular tubercles, at periphery with irregular granules and tubercles oriented toward equator; proximal face with ± anastomosed granules, triradiate scar weak or indistinct.

Discussion:Riccia vitalii resembles R. weinionis and R. ridleyi in that the cells of the dorsal thallus tissue have 2 longitudinal wall thickenings. The 3 species are distinguished by spore shape and ornamentation: in R. weinionis and R. ridleyi the spores are tetrahedral, less than 125 µm in diam., and the proximal face is areolate; in R. vitalii they are subspherical or subtetrahedral, 92-150 µm in diam., and the proximal face is granulose. Riccia weinionis differs from R. ridleyi by the fewer areoles on the spores, both on the distal face (7-9 across diam.; in R. ridleyi 10-12) and on the proximal face (15 areoles per facet; 30-50 in R. ridleyi).

Distribution and Ecology: Riccia vitalii is known from Costa Rica, Brazil (Alagoas, Amazonas, Bahía, Ceará, Espíritu Santo, Goiás, Maranhão, Mato Grosso do Sul, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Sergipe), and Paraguay. The species seems quite common in Brazil and has been collected on acidic soil over granitic rocks or sandstone, exposed in dry grasslands, on water edges, also along roadsides and in towns, or partially shaded in open caatinga vegetation, from sea level to 400 m.

Distribution:Amazonas Brazil South America| Paraíba Brazil South America| Maranhão Brazil South America| Goiás Brazil South America| Mato Grosso do Sul Brazil South America| Alagoas Brazil South America| Bahia Brazil South America| Piauí Brazil South America| Pernambuco Brazil South America| Rio Grande do Norte Brazil South America| Sergipe Brazil South America| Espirito Santo Brazil South America| Ceará Brazil South America| Paraguay South America| Guanacaste Costa Rica Central America|