Cyclodictyon varians (Hedw.) Kuntze

  • Authority

    Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

  • Family

    Pilotrichaceae

  • Scientific Name

    Cyclodictyon varians (Hedw.) Kuntze

  • Description

    Species Description - Plants rather small to medium-sized, in ± lustrous, whitish green to yellow-green, thin, sometimes extensive, flat mats. Stems creeping, to ca. 3 cm long, irregularly to pinnately branched, complanate-foliate; in cross-section with a unistratose hyalodermis over 1-3 rows of medium-sized firm-walled cells surrounding larger thin-walled cells, central strand none; axillary hairs 2-celled, both hyaline, with a short basal one and an elongate apical one. Leaves not or only scarcely contorted when dry, lateral leaves wide-spreading dry or moist, lanceolate to ovate to oblong-lanceolate or oblong-ovate, 1.4-1.7(-2) mm long, obscurely asymmetric, gradually acuminate, dorsal leaves erect to erect-spreading, ovate, 1.2-1.7 mm long, ± symmetric, gradually acuminate; margins bordered by a single row of narrow, elongate cells, united at apex but not forming an apiculus or with a single-celled apiculus, entire to serrulate, often ± zig-zag above, plane; costa double, ending ca. 2/3 the leaf length, tapering distally, not projecting at apex or projecting as a small prickle; cells large, lax, hexagonal, thin-walled, 1 (-2): 1, 43-57(-85) X 34-43 µm, <15 between costal tips, often 7-12, usually not differentiated in apex except sometimes a single cell somewhat narrower, becoming longer and rectangular toward the insertion; alar cells not differentiated. Asexual propagula unknown. Autoicous or synoicous. Perichaetia small, inconspicuous, along stems; leaves pale, ± erect, lanceolate, 0.7-1.3 mm long, gradually acuminate; margins bordered by a single row of narrow, elongate cells united at apex into a 1-3-celled apiculus, ± entire, plane; costa double, the forks ± parallel, ending 1/2-3/4 the leaf length; cells long-hexagonal, ca. 3:1, thin-walled, scarcely differentiated toward insertion. Setae elongate, smooth, yellowish above, reddish at base, 1.2-1.8 cm long, curved at extreme apex; capsules inclined to horizontal, short-cylindric, arcuate and asymmetric when dry and empty, 1.3-2 mm long; exothecial cells subquadrate to short-rectangular, the vertical walls firm, the horizontal ones thin, obscurely collenchymatous; annulus none; operculum long-rostrate from a high-conic base, the rostrum pale; exostome teeth reddish, bordered, on the front surface with a broad median furrow, the furrow pale with a zig-zag median line, the plates cross-striolate below, coarsely papillose above, trabeculate at back; endostome yellowish, with a relatively high, papillose basal membrane, segments spiculose, keeled, narrowly perforate above, with baffle-like crosswalls, ca. as long as the teeth, cilia none. Spores spherical, low-papillose, 8.5-15 µm diam. Calyptrae mitrate, constricted and lobed at base, naked, smooth.

  • Discussion

    1. Cyclodictyon varians (Sull.) Kuntze, Revis. Gen. PI. 2: 835. 1891; Hookeria varians Sull., Proc. Amer. Acad. Arts 5; 285. 1861. Plate 9, figures 1-3 Hookeria blanda Lorentz, Moosstudien 166. 1864; Cyclodictyon blandum (Lorentz) Kuntze, Revis. Gen. Pl. 2: 835. 1891. Hookeria antillarum Mitt., J. Linn. Soc., Bot. 12: 343. 1869; Cyclodictyon antillarum (Mitt.) Kuntze, Revis. Gen. Pl. 2; 835. 1891. Cyclodictyon cubense R. S. Williams, Bull. Torrey Bot. Club 34: 574. 1908. Discussion. This species has been widely misinterpreted and misidentified throughout tropical America. Specimens so identified from Bermuda and all those examined from Puerto Rico have been wrongly named. The species has been reported from throughout Central America and northern South America. All such named Brazilian specimens examined have proved to be C. olfersianum (Hornsch.) Kuntze. There is some confusion with this species since Homschuch (1840) described it as having a smooth calyptra but illustrated a rough one. Although Vegetatively close to C. varians, the species differs in having leaves with a longer, several-celled apiculus. Cyclodictyon varians is characterized by its very large leaf cells (the largest of any species in the West Indies), its one-celled border confluent at the apex but not forming an apiculus or forming a single-celled one, and its slender costa, usually not projecting as a spine. It most closely resembles C. albicaule, which also usually has a slender costa and a subentire border, often of a single row of cells. However, in C. albicaule the leaves are broader and more asymmetric and the border is of shorter cells that form a several-celled apiculus. Our other two large-celled Cyclodictyon species, C. albicans and C. bicolor, have toothed margins and strong, projecting costae. West Indian reports of Cyclodictyon cuspidatum Kuntze are referrable here.

  • Distribution

    Range. United States (Florida, Louisiana); Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic); growing on rotting wood, humus, and limestone, in humid forests, at low to median elevations, almost always below 1000 m. Additional distribution in tropical America has not been verified.

    United States of America North America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America|