Taxithelium pluripunctatum (Renauld & Cardot) W.R.Buck
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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
Sematophyllaceae
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Scientific Name
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Description
Species Description - Plants medium-sized, in somewhat lustrous, wiry, golden, lax, extensive mats. Stems creeping, to ca. 10 cm long, freely but irregularly branched, not or scarcely complanate-foliate; in crosssection with 1-2 rows of small thick-walled green cells surrounding large thin- to firm-walled cells, central strand absent; pseudoparaphyllia foliose; axillary hairs with a single short brown basal cell and 2 elongate hyaline distal cells. Stem and branch leaves somewhat differentiated, the stem leaves somewhat longer, longer acuminate, and less papillose than the branch leaves, the branch leaves laxly disposed, wide-spreading, lanceolate-ovate to ovate, 0.75-1.1 X 0.2-0.35 mm, acuminate, somewhat concave; margins subentire to distantly serrulate to base, plane; costa short and double or absent; cells linear, seriately pluripapillose with 2-5 papillae over each lumen at back, the papillae small and blunt, ± firm-walled, obscurely porose, becoming smooth in the acumen, becoming oblong, smooth, thick-walled, and porose in a single row across the insertion; alar cells not differentiated or with 1-2 oblong cells at the margins. Asexual propagula none. Autoicous. Perichaetia on branches; leaves erect, narrowly triangular to oblong-triangular, 1-1.3 mm long, acuminate; margins serrulate throughout, more sharply so above, plane; costa mostly none; cells linear, smooth, thick-walled, porose, becoming rectangular toward the insertion; alar cells not differentiated. Setae elongate, slender, smooth, orange, 0.7-1.3 cm long, slightly curved at base of urn; capsules inclined, somewhat asymmetric, ovoid, ca. 0.8 mm long, with a slightly differentiated neck; exothecial cells subquadrate, slightly collenchymatous, becoming small, oblate and evenly thinwalled in 3-4 rows at the mouth; annulus not differentiated, operculum short-rostrate; exostome teeth narrowly triangular, shouldered, bordered, on the front surface with a zig-zag median line, cross-striolate below, coarsely papillose above, trabeculate at back; endostome with a high basal membrane, segments yellow, finely papillose, broad, keeled, perforate, almost as long as the teeth, cilia single. Spores spherical, finely papillose, 15-18 µm diam. Calyptrae cucullate, naked, smooth.
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Discussion
3. Taxithelium pluripunctatum (Renauld & Cardot) W. R. Buck, Moscosoa 2: 60. 1983; Trichosteleum pluripunctatum Renauld & Cardot, Bull. Soc. Roy. Bot. Belgique 29(1): 184. 1890. Plate 142, figures 1-6 Taxithelium thelidiellum Besch., J. Bot. (Morot) 16: 10. 1902. Taxithelium patulifolium Thér. in Thér, Dixon & H. Buch, Ann. Bryol. 7: 160. 1934. Discussion. Taxithelium pluripunctatum is very much in aspect like a Mittenothamnium, such as M. reptans, due to its lax, wiry growth form. However, the seriately pluripapillose laminal cells leave little doubt as to its affinities. It is separated from our other two species by the wide-spread, laxly disposed leaves with alar cells not or only scarcely extending up the margins, but rather with a row of oblong, thick-walled, porose cells across the insertion. Taxithelium patulifolium is supposedly differentiated by only minor characters, such as a shorter seta and less toothed perichaetial leaves. The type specimen, however, is virtually identical to that of T. pluripunctatum.
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Distribution
Range. Brazil, French Guiana, Trinidad; Dominica, Martinique; on bases of trees, humus, and limestone, in humid forests, at 200-900 m.
Brazil South America| French Guiana South America| Trinidad and Tobago South America| Dominica South America| Martinique South America|