Monographs Details: Marchantia papillata Raddi
Authority: Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)
Synonyms:Marchantia pusilla Nees, Marchantia subandina Spruce, Marchantia papillata subsp. papillata
Description:Species Description - Thallus yellowish or dark green, usually 2.4-3.4 mm wide, usually with narrow, black median band on dorsal side. Margins usually purplish, cell walls thin. Epidermal pores usually 50-84 µm diam., inner opening bounded by cells with straight or slightly convex inner walls. Basal tissue with numerous, purplish sclerotic cells, without mucilage cavities. Ventral scales in 4 rows; appendage of median scales purplish, orange or hyaline, triangular (ratio length/width usually 1-1.7:1), (6-)8-14 cells wide, acute or apiculate, with row of (1-)2-3 cells apically, margins toothed, teeth mostly unicellular, usually 1.8-3.4 times smaller than inner cells, without oil cells; laminal scales purplish or hyaline. Gemma cups nearly entire, crenulate or with some irregular cilia, 1-2 cells long, without papillae on outer side. Stalks of gametangiophores not sheathed basally by large scales. Antheridiophore stalk with 1 narrow, often interrupted band of air chambers or without band, and 2 rhizoid furrows; receptacle palmate, usually 3.5-5.5 mm diam., deeply dissected into 4-7 rays, without papillae on dorsal side. Archegoniophore stalk with single, broad band of air chambers, sometimes splitting into 2 bands, and 2 rhizoid furrows; receptacle nearly symmetrical, usually 3.2-4.4 mm diam., with rounded median projection dorsally, deeply dissected into 5-9 lobes, lobes strongly convex basally, broadened apically; scales of receptacle with sinuose cells apically, ending in row of 1-2 cells. Involucres hyaline at margin, entire or irregularly crenulate. Spores yellow or brown, 24-26 µm diam., with smooth ridges. Gametophytic chromosome number n = 9.

Discussion:The species is common only in SE Brazil, rare elsewhere, and grows on soil and soil over rocks, often near water edges, mainly at low elevations (0-500 m), but has been collected up to 1200 m in Argentina.

Marchantia papillata comprises 2 subspecies, the neotropical subsp. papillata and the Asiatic subsp. grossibarba (Steph.) Bischl., distinguished mainly by the shape of the appendage of the median scales. Additionally, subsp. grossibarba is more robust, nearly all parts of the plants being larger, and the lobes and rays of the female and male receptacles are more numerous.

The shape of the female receptacle, with lobes costate basally and broadened apically, separate M. papillata subsp. papillata from the other species of subgen. Chlamidium. The scales of the female receptacle have sinuose cells apically. Spore wall ornamentation in M. papillata is also distinctive.

Marchantia papillata subsp. papillata is most closely related to M. inflexa, and sometimes the 2 have been considered conspecific (see under the latter species).

Distribution and Ecology: Marchantia papillata subsp, papillata is known in the Neotropics from 2°S to 35°S, from Ecuador (without locality), Peru (Huanuco, Lima (Carrillo & Chanco, 1971), San Martin), Brazil (Amazonas, Mato Grosso, Minas Gerais, Paraná, Rio de Janeiro, Rio Grande do Sul (Vianna, 1976), Santa Catharina, Sao Paulo), Bolivia (Santa Cruz, Tarija), Chile (without locality), Paraguay, Argentina (Buenos Aires, Córdoba, Jujuy, Misiones, Tucumán (Hässel de Menéndez, 1963)), to Uruguay (Hässel de Menéndez, 1964).

Distribution:Amazonas Brazil South America| São Paulo Brazil South America| Mato Grosso Brazil South America| Rio de Janeiro Brazil South America| Santa Catarina Brazil South America| Minas Gerais Brazil South America| Paraná Brazil South America| Jujuy Argentina South America| Córdoba Argentina South America| Buenos Aires Argentina South America| Misiones Argentina South America| Ecuador South America| Chile South America| Santa Cruz Bolivia South America| Tarija Bolivia South America| Central Paraguay South America| Paraguarí Paraguay South America| Huánuco Peru South America| San Martín Peru South America|