Calypogeia Raddi
Kantius Gray, Nat. Arr. Brit. Pl. 1: 706. 1821.
Cincinnulus Dumort., Commentat. Bot. 113. 1822.
Parentia Léman, Dict. Sci. Nat. 37: 536. 1825.
Type: Calypogeia fissa (L.) Raddi (≡Mnium fissum L.)
Plants usually lax and delicate, typically whitish or pale green, rarely feebly blue-green, lacking brownish pigments, translucent. Branching irregular, remote, mostly ventral-intercalary, leafy and not stoloniform; Frullania -type branches usually present, the branches rarely of Acromastigum or Microlepidozia types. Stem usually with both cortex and medulla thin-walled, rarely with a single-layered cortex of slightly firm-walled cells. Leaves soft-textured, ± hyaline, pellucid, plane or slightly convex, unlobed and entire or bidentate, without a border of differentiated cells. Cells large, rather pellucid, usually very thin-walled and devoid of trigones, or, less often, trigones small, concave-sided, rarely slightly bulging; surface smooth or finely papillose. Oil-bodies 2–10(13) per cell, hyaline, bluish in a few species, botryoidal and usually few-segmented (rarely finely botryoidal). Underleaves typically bilobed, at times unlobed but the lobes each reduced to a slime papilla, the underleaves usually with a conspicuous rhizoid-initial area at base. Asexual reproduction by greenish, delicate, 1–2-celled gemmae from erect, reduced-leaved shoots.
Dioecious or autoecious. Androecia with antheridia 1–2(3) per bract. Marsupium fleshy, cylindrical, pale, densely rhizoidous, the summit with a few, vestigial bractlets.
Capsule cylindrical, the valves spirally twisted, linear, bistratose.
A nearly cosmopolitan genus with ca. 35 species. The genus is recognized here in the more narrowly defined sense of Schuster (1995c, 2000a) that excludes subg. Caracoma Bisch. and subg. Mnioloma (Herzog) Bisch. About 15 species occur in tropical America (Gradstein et al., 2001) and nine occur in eastern North America (Schuster, 1969c). One species, Calypogeia sphagnicola, is bipolar in distribution; in the Southern Hemisphere it is known from southern South America, New Zealand and Tasmania (Schuster, 1969c; Engel, 1978). Bischler (1970) included five species (currently recognized as Calypogeia) for South Africa; of these C. bidentula (F.Weber) Nees, C. longifolia Steph. and C. microstipula (Steph.) Steph. are endemic to Africa, C. arguta Nees & Mont. is also present in Europe and C. fissa (L.) Raddi occurs in Europe and North America. Other species included in the genus by Bischler have subsequently been excluded from the genus.
References: Hodgson (1967); Schuster (1969c, 1995c, 2000a).
