Monographs Details: Homalia
Authority: Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
Description:Genus Description - Plants slender to robust, in lustrous, mostly dark metallic green, sometimes yellow-green or golden mats. Primary stems creeping secondary stems arising from upturning primary stem, the creeping stem continuing by innovations, the secondary stems prostrate to erect, simple to irregularly pinnate, sometimes flagellate, complanate-foliate; in cross-section with small thick-walled cells surrounding large thinner-walled cells, central strand not or poorly differentiated; paraphyllia absent; pseudoparaphyllia filamentous to foliose-axillary hairs with 1-2 short brown basal cells and 3-6(-10) elongate hyaline distal cells. Primary creeping stem leaves mostly reduced secondary stem and branch leaves similar, complanate, wide-spreading, asymmetrically oblong to spathulate, sometimes obovate to ± orbicular, obtuse, apiculate to mucronate, sometimes decurrent, often auriculate on one side; margins subentire to coarsely serrate above, entire to subentire below, often indexed on one side below; costa single, ending 1/3-4/5 the leaf length, or short and double; cells rhomboidal to linear, smooth, thin- to thick-walled, sometimes porose, shorter toward the leaf apex, becoming more elongate toward the insertion; alar cells scarcely differentiated. Asexual propagula none. Autoicous, dioicous, or rarely synoicous. Perichaetia without ramenta; leaves erect, convolute, ovate; margins mostly toothed above, entire to subentire below, plane; costa mostly short and double or none, rarely single and weak; cells mostly elongate, smooth, ± thick-walled, ± porose. Setae elongate, smooth, yellowish, often flexuose; capsules erect to suberect, shortly broad-cylindric to cylindric, ± arcuate; exothecial cells short-rectangular, thick-walled, not collenchymatous, becoming shorter toward the mouth; annulus well developed, of a single fragmenting row of deciduous cells; operculum short- to long-rostrate, straight to oblique; peristome attached near the mouth, exostome teeth on the front surface cross-striolate below with overlying papillae, papillose above, strongly trabeculate at back; endostome with a high basal membrane, segments papillose, keeled, perforate, ca. as long as the teeth, cilia well developed, in groups of 2-4, nodulose, occasionally rudimentary. Spores spherical, papillose. Calyptrae cucullate, naked, smooth.
Discussion:Homalia (Brid.) Bruch & Schimp. in Bruch, Schimp. & W. Gümbel, Bryol. Eur. 5(fasc. 44-45, Monogr. 1): 53. 1850, “Omalia", corr. Schimp., Syn. Musc. Eur. 571. 1860, non Omaha Lobarz., Naturwiss. Abh. (Vienna) 1: 48. 1847 [13 Aug; = Neckera], nom. inval., nec Omaha Wilson, Ann. Mag. Nat. Hist. 20: 379. 1847 [Dec; = Isodrepanium], nom inval.; Leskea subgen. Omaha Brid., Bryol. Eur. 2: 329. 1827; Hypnum sect. Omaha (Brid.) Müll. Hal., Syn. Muse. Frond. 2: 233. 1851; Neckera sect. Omaha (Brid.) Mitt., J. Proc. Linn. Soc., Bot. Suppl. 1: 117. 1859; Homalia subgen. Eu-Homalia Broth, in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 848. 1906, nom. illeg.
Discussion. Homalia is a small genus of about eight species, with its highest diversity in the Iberian Peninsula and Macaronesia. In our flora it is represented by a single species. It is characterized by glossy, complanate-foliate plants. The leaves are obtuse. The setae are elongate and the capsules have mostly well-developed peristomes of cross-striolate teeth and cilia-bearing endostomes.
The genus was revised recently by He (1992). He restricted Homalia to just subgen. Homalia, whereas subgen. Spathularia Broth, was recognized as a separate genus, Penchilothecium (cf. Enroth & He, 1991).