Rhynchostegiopsis tunguraguana (Mitt.) Broth.
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Authority
Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
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Family
Leucomiaceae
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Scientific Name
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Description
Species Description - Plants medium-sized to fairly robust, in lustrous, pale-green (becoming golden with age), often extensive, lax mats. Stems creeping or scrambling, to ca. 7 cm long, mostly ca. 4 cm long, fragile, irregularly and little-branched, the stem and branch apices often cuspidate, complanate-foliate; in cross-section 1-3(-4) rows of small to medium-sized thin-walled cells surrounding larger thin-walled cells, central strand none; pseudoparaphyllia none; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Leaves not contorted when dry, falcate with leaf apices pointing toward substrate, erect-spreading, lanceolate-ovate to ovate, 2-2.5(-2.8) mm long, gradually acuminate, the lateral leaves more slenderly so, concave; margins not bordered, serrulate to serrate above, more strongly so in dorsal leaves, entire below, plane above, usually erect below; costa none or occasionally short and double; cells linear, subflexuose, smooth, thin- to firm-walled, somewhat shorter in the acumen, becoming shorter 1-2 rows across the insertion; alar cells not differentiated. Asexual propagula none. Dioicous, rarely fertile. Perichaetia small, inconspicuous, on older stems; leaves erect with spreading apices, broadly oblong-lanceolate, 0.85-1.5 mm long, gradually acuminate; margins not bordered, serrulate above, entire below, plane; costa none; cells long-hexagonal, smooth, thin-walled, lax, becoming shorter toward the insertion. Setae elongate, smooth, reddish, ca. 2 cm long, curved at apex; capsules inclined to horizontal, broadly cylindric, ca. 2 mm long, smooth at neck; exothecial cells short-rectangular, the vertical walls thick, the horizontal ones thin, obscurely collenchymatous; annulus and operculum not seen; exostome teeth narrowly triangular, narrowly bordered, not shouldered, on the front surface with a broad pale median furrow with a zig-zag line down it, the plates densely cross-striolate below, moderately papillose above, slightly trabeculate at back, densely and finely papillose; endostome with a fairly high, smooth basal membrane, segments finely spiculose, keeled, narrowly perforate, with baffle-like crosswalls, ca. as long as the teeth, cilia in groups of 1-2, somewhat nodose, finely roughened, ca. 1/2 as long as the segments. Spores spherical, finely papillose, 13-17 µm diam. Calyptrae not seen.
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Discussion
2. Rhynchostegiopsis tunguraguana (Mitt.) Broth, in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 1235. 1909; Stereodon tunguraguanus Mitt., J. Linn. Soc., Bot. 12: 534. 1869. Plate 37, figures 8-12 Rhynchostegiopsis lutescens E. Britton ex Broth, in Engl., Nat. Pflanzenfam., ed. 2, 11: 263. 1925; Rhynchostegiopsis planifolia H. A. Crum & E. B. Bartram, Bull. Inst. Jamaica, Sci. Ser. 8: 55. 1958, nom. illeg. Discussion. Rhynchostegiopsis tunguraguaiw is characterize by its robust, complanate-foliate habit and leaves often pointing toward the substrate. The leaves are ovate, sometimes narrowly so, with a serru ate to serrate, nonflexuose apex. The leaf cells are linear and become shorter in the acumen. The species differs from R. flexuosa in the more robust, complanate-foliate plants growing on the ground at very high elevations. The leaves are broader and with a shorter, broader acumen. Rhynchostegiopsis tunguraguuna may be confused with an Ectropothec-ium because of its falcate, serrate leaves, but may be separated by having completely ecostate leaves with broader cells and no alar development. Stem cross-sectional differences can provide confidence in questionable specimens because in Ectropothecium there is an outer layer of small thick-walled cells. This species is best known as a supposed Jamaican endemic (recently discovered in the Dominican Republic) under the name R. planifolia. However, like many high-elevation, Greater Antillean “endemics,” older names can be found in the Andean literature.
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Distribution
Range. Mexico, El Salvador, Honduras, Colombia, Ecuador, Peru; Jamaica, Hispaniola (Dominican Republic); mostly growing on the ground,
Mexico North America| El Salvador Central America| Honduras Central America| Colombia South America| Ecuador South America| Peru South America| Jamaica South America| Dominican Republic South America|