Revision of the Genus Rozea (Musci)

Abstract

Rozea is a small genus of pleurocarpous mosses which occurs in the highlands of Mexico, Central America, northern South America and Himalayan Asia. The species are, at best, ill-defined, and the genus has been overclassified. We recognize R. chrysea Besch. (syn. R. stricta Besch.), R. chrysea fo. andrieuxii (C. Muell.) stat nov., R. chrysea var. bourgaeana (Besch.) stat. nov. (syn. R. schimperi Besch. and R. viridis Besch.) and R. subjulacea Besch. in the Americas. The Asiatic species are R. pterogonioides (Harv.) Jaeg. (syn. R. myura Herz.), R. microcarpa Broth., R. microcarpa fo. elongata fo. nov. and R. kenoyeri n. sp. (from Uttar Pradesh, India). Rozea diversifolia Broth. appears to be a Homalothecium. Rozea roseorum Williams is a Juratzkaea species. Micrographs of peristomes provide evidence that Rozea may have some relation- ship to the hypnoid group of families rather than to the Entodontaceae. Rozea is a small moss genus which occurs disjunctively in the highlands of tropical America, from Mexico to northern South America, and in Himalayan Asia. The species are difficult to define, especially in sterile condition, but the genus is easily recognizable. The plants, in aspect similar to Brachythecium or Orthothecium, are relatively slender and shiny, golden to red-bronze or sometimes (apparently in shade forms) green. Creeping stems are freely branched, and the branches are subjulaceous, ascending and often curved. Leaves characteristically have two well-marked plicae or a single median fold. Leaf margins are revolute, nearly throughout, and serrulate near the apex. The costa is single but sometimes forked. Leaf cells are smooth and linear-rhomboidal in the upper regions but short and broad in two to six rows across the insertion. Alar regions extend downward as short decurrencies which merge with short, broad, hyaline cells of the stem epidermis which strips off with the leaves on dissection. Capsules are erect and sym- metric, with a somewhat reduced peristome of hypnoid structure (Fig. 5-6). The exostome teeth are cross-striolate below. Segments of the endostome which are rather broad and keeled, arise from a fairly well-developed basal membrane. Cilia are lacking or rudimentary. Because of the hypnoid nature of the peristome, a relationship to Entodon seems questionable. Even though Fleischer (1915), Brotherus (1925) and more recent authors, e.g. Mizushima, 1960, included Rozea in the Entodontaceae, it may have closer ties with some of the Hypnaceae with erect capsules and variously reduced peristomes, such as Ctenidiadelphus cylindricarpus (Card.) Bartr. (Fig. 3-4). In its best development the hypnoid peristome has the following features: exostome teeth abruptly tapered, bordered