Sphaerocarpos

• Authority

  Bischler, Hélène, et al. 2005. Marchantiidae. Fl. Neotrop. Monogr. 97: 1--262. (Published by NYBG Press)

• Family

  Sphaerocarpaceae

• Scientific Name

  Sphaerocarpos

• Description

  Genus Description - Thalli prostrate, small and delicate, pale green, less than 1 cm long, without air chambers and pores, thickened in the middle, unistratose toward the margins, the margins sinuose-lobed, the median thallus surface of fertile plants covered by numerous swollen involucres. Dioecious; female and male thalli quite different in size and shape. Female thalli suborbicular, 5-8 mm long, involucres 1-2 mm long, obovate to cylindrical, with a very narrow mouth. Male thalli smaller, 1-3 mm long, elongate and forked-lobed, involucres tiny, less than 1 mm long, flask-shaped. Spores large, often in tetrads, yellow-brown, tetrads 100-180 µm in diam., surface of individual spores covered by a fine network of areoles, the areoles 6-12 µm in diam.. Asexual reproduction by specialized devices lacking.

• Discussion

  Sphaerocarpos is a widespread Subtropical-Mediterranean genus of about 12 species. One species, S. muccilloi Vianna (Fig. 158G-J) has been recorded from Rio Grande do Sul, S Brazil (Vianna, 1981; Gradstein & Pinheiro da Costa, 2003), and an unidentified species of Sphaerocarpos has been reported from the surroundings of Lima in Peru (Carillo & Chanco, 1971). Additional species of Sphaerocarpos have been recorded from the S United States, Uruguay, Argentina, and Chile (e.g., Gradstein et al., 1983; Schuster, 1992b). The Peruvian record is of considerable importance, because it is the only one of the order Sphaerocarpales within the boundaries of the Neotropics. The identity of the Peruvian specimen remains unknown, however; material could not be found in the Herbarium of the Universidad Nacional Mayor de San Marcos, Lima (J. Opisso, pers. comm., 8. April 2003). A field search in potentially suitable habitats in Peru should be undertaken to trace this important taxon. The species of Sphaerocarpos usually grow on temporarily moist, compact soils in slightly shaded, rather arid places. The small, prostrate thalli densely covered by numerous swollen involucres are unmistakable.