Reboulia Raddi, Opusc. Sci. Bologna. 2: 357. 1818.
[orthography conserved "Rebouillia"; For de Reboul, Italian botanist]
Marie L. Hicks
Plants in depressed mats, dichotomously branched with occasional apical or lateral adventitious branches of ventral origin; green to dull green with purplish margins, underside purple; dorsal surface firm, not areolate; with slightly elevated air pores. Thalli 10 18 cells thick medially, gradually tapering to the margins, the interior tissue with few oil cells; air chambers simple, without photosynthetic filaments; dorsal epidermis without oil cells, epidermal cells with thin walls and distinct trigones, air pores surrounded by 3 6 concentric rings of cells with thickened walls and trigones; ventral scales in 2 rows, purple, lunate, with scattered oil cells and few slime papillae along the margins; appendages purplish with decolorate apices, linear, hair like; rhizoids dense along ventral midline, smooth or with internal pegs. Specialized asexual reproduction absent. Sexual condition monoicous; androecia dorsal, sessile, distinct, discoid to reniform or lunate, thickened, purplish, ringed by small subulate purple scales; gynoecia terminal, in apical notch, gynoecial stalk with one rhizoid furrow and white hair like scales at base and apex; carpocephalum hemispheric, the proximal half lobed, each lobe with a 2-labiate slit, and containing one sporophyte; pseudoperianth absent. Sporophyte seta not elongating. Capsule spherical, irregularly circumscissile, the distal portion disintegrating; capsule wall without thickenings. Spores areolate, the areolae bordered by winglike ridges; elaters 2 4 spiral.
Species 2 (1 in the flora): worldwide except Antarctica, on soil.
The genus can be recognized by the conspicuous cluster of white hair like scales at both the base and apex of the gynoecial stalk and by the very narrow, hair like scale appendages.
Evans, A. M. 1923. Rebouliaceae. In C. C. Haynes, M. A. Howe and A. W. Evans. 1923. Sphaerocarpaceae--Marchantiales, Sphaerocarpaceae, Riellaceae, Ricciaceae, Corsiniaceae, Targioniaceae, Sauteriaceae, Rebouliaceae, Marchantiaceae. North American Flora Ser. I, Vol. 14(1). New York Botanical Garden, New York. Frye, T. C. and L. Clark. 1937. Hepaticae of North America. University of Washington Publ. in Biology, University of Washington, Seattle. Schuster, R. M. 1992. The Hepaticae and Anthocerotae of North America. Vol. 6. Field Museum of Natural History, Chicago.