Monographs Details: Bazzania
Authority: Fulford, Margaret H. 1963. Manual of the leafy Hepaticae of Latin America--Part I. Mem. New York Bot. Gard. 11: 1-172.
Description:Genus Description - Plants in tufts or depressed mats, bright green, olive-green, golden-yellow, reddish, or brown; stems filiform to robust, the lateral branches of the Frullania type forming apparent dichotomies, subtended by an ovate, acute dorsal halfleaf ; ventral branches intercalary, in the axils of underleaves, flagelliform, long, filiform with scale-like leaves; stem in transverse section little differentiated; rhizoids colorless, from the scales of the flagelliform branches, the lower portions of the female bracts, or rarely from the underleaves. Line of leaf insertion oblique, straight to strongly curved in its upper part, in some becoming hook-formed. Leaves incubous, alternate (rarely opposite), asymmetric, ovate to lanceolate, the dorsal base convex to cordate, the ventral base often more or less auricled, the apex truncate, 2-3-toothed (rarely 4-toothed), in a few species undivided; leaf-margins entire, rarely serrate to spinose-dentate, sometimes ciliate or appendiculate at the ventral base; leaf-cells quadrate to hexagonal, the walls thin or thickened and containing pits; trigones very small to large, often coalesced; a vitta of larger cells present in some species; cuticle smooth to verruculose. Underleaves quadrate, elongate to ovate, sometimes cordate at the base, the line of attachment transverse or recurved, in some connate with leaves on one or both sides, the apex rounded-entire to 2-4-toothed or -lobed, or variously incised, the margins entire, crenulate, spinose-dentate to ciliate. Plants dioicous, the sexual branches short, ventral, intercalary, axillary; male branches catkinlike, the bracts ovate, concave, bilobed to bispinose, the bracteoles slightly smaller, plane; antheridia one or two; female branches solitary, the bracts and bracteoles in three or four series, unlike the leaves, orbicular-ovate to ovate-lanceolate. Perianth to 6 cm long, ovoid-cylindric, terete below, trigonous and of a single layer of cells above, often with additional folds, the mouth of three ciliate to dentate lobes, usually contracted. Sporophyte capsule oblong-ovoid, the wall usually of five layers, the outermost layer with brown thickenings as knots along the vertical walls, the innermost layer with brown thickenings as half-rings or bands on the inner tangential walls; capsule-stalk with an outer layer of 16 large cells surrounding many smaller cells; spores small, brown; elaters long, slender, bispiral. Sporeling of the Nardia type. Vegetative reproduction by means of leafy shoots from cylindric protonemata from cells of ordinary or caducous leaves and underleaves.
Discussion:Pleuroschisma Dumortier, Syll. Jungerm. 68. 1831.
Herpetium C. G. Nees, Nat. Eur. Leberm. 1: 96. 1833.
Mastigobryum Nees, Lindenberg & Gottsche, Syn. Hep. 214. 1845.
Type species: Jungermannia trilobata.
This large genus is most abundant in tropical and subtropical regions, with a few species extending northward into the Northern Hemisphere, or southward from the tropics. It is easily recognized in the field because of the apparent dichotomies of the stem, the ventral flagelliform branches, the incubous leaf arrangement, the usually three-toothed leaves, and the conspicuous underleaves. Unfortunately, it is much more difficult to recognize many of the species, for most of them are exceedingly variable, as Spruce (1885) has pointed out. This variation is more than habitat modification, and is often so extreme among the plants of different areas, or even between male and female plants, that the limits of certain taxa have been established on a more or less arbitrary basis.
The genus appears to be an old one, since there are two easily recognized subgenera and six sections, and the distribution patterns of groups of species, or of individual species, are often localized or discontinuous. A number of species have an Antarctic distribution.