Thamniopsis incurva (Hornsch.) 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
Pilotrichaceae
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Scientific Name
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Description
Species Description - Plants medium-sized, in ± lustrous, whitish green to purplish, often dense, extensive mats. Stems creeping, to ca. 6 cm long, freely but irregularly branched, sometimes ± pinnate, laxly foliate, complanate-foliate; in cross-section with 1(-2) rows of large, thin-walled cells over 2-4 rows of small firm-walled cells surrounding numerous large thin-walled cells, central strand none; pseudopa-raphyllia present, the inner ones filamentous, the outer ones developing later and foliose; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Lateral and dorsal/ ventral leaves differentiated, usually ± contorted when dry, the lateral ones wide-spreading, often asymmetric, broadly oblong to oblong-ovate, 1.7-2.2 mm long, sometimes shorter on branches, broadly obtuse, the dorsal/ventral ones erect, symmetric, ovate to obovate to oblong-ovate, 1-1.7 mm long, broadly obtuse to ± rounded-acute; margins serrate, the teeth mostly bifid, swollen, all cells in upper 1/2-2/3, of leaf (and further down on acropetal margin of lateral leaves) short and forming teeth, below these marginal cells becoming longer and not toothed but forming a border of 13 rows, sometimes with 1(-3) rows of elongate cells subtending upper short marginal teeth, plane but basiscopic basal margin often turned under on lateral leaves; costa double, ± diverging throughout, ending 1/2-2/3 the leaf length, somewhat unequal, often projecting at extreme apex as a small spine; upper cells hexagonal or rarely rhomboidal, 1-2:1, smooth, thin-walled, often slightly porose, in lower 1/3-1/2 (especially of lateral leaves) becoming long-hexagonal to rectangular, ca. 5:1, more obviously porose, otherwise not differentiated at insertion, not colored; alar cells not differentiated. Asexual propagula none. Autoicous or synoicous. Perichaetia inconspicuous; leaves few, ± erect, broadly and bluntly acuminate from a short, oblong base, 1.3-1.7 mm long, obtuse to acute; margins bordered by 1-3 rows of elongate cells, serrate in extreme apex, the teeth ± bifid, subentire below, plane; costa none or double and ending ca. 1/3 the leaf length; upper cells hexagonal, ca. 3-4:1, firm-walled, porose, becoming long-hexagonal to rectangular below, ca. 6:1, thinner-walled near insertion. Setae elongate, roughened at extreme apex, 2-2.8 cm long, somewhat flexuose, curved at extreme apex; capsules inclined to pendent, cylindric, 1.5-2.5 mm long; exothecial cells rectangular, thick-walled, evenly thickened or with horizonal walls thinner; annulus well developed, of l(-2) rows of large, hyaline, thick-walled cells subtending numerous (>10) rows of thin-walled, rectangular cells with nodosely thickened walls, sometimes falling with the operculum; operculum long-rostrate from a high-conic base; exostome teeth reddish brown, not or narrowly bordered, on the front surface with a median furrow with a zig-zag line down it, the plates cross-striolate below, with small overlying papillae near midtooth, ± smooth to densely papillose above shoulder, not or scarcely trabeculate at back, papillose; endostome with a high, smooth to finely papillose basal membrane, segments papillose to spiculose, keeled, not perforate, with baffle-like crosswalls, ca. as long as the teeth, cilia none. Spores spherical, finely papillose to almost smooth, 8.5-12 pm diam. Calyptrae mitrate, covering ca. 1/2 of urn, irregularly lobed at base, sparsely hairy, the hairs hyaline, uniseriate, 5-8-celled, the distal cells longer than basal ones, ± smooth or somewhat roughened above.
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Discussion
1. Thamniopsis incurva (Hornsch.) W. R. Buck, Brittonia 39: 218. 1987; Chaetephora incurva Homsch. in Nees, Horae Phys. Berol. 65. 1820; Hookeria incurva (Homsch.) Hook. & Grev., Edinburgh J. Sci. 2: 231. 1825; Lepidopilum incurvum (Hornsch.) Müll. Hal., Linnaea 21: 195. 1848; Callicostella incurva (Hornsch.) Angstr., Öfvers. Förh. Kongl. Svenska Vetensk.-Akad. 33(4): 27. 1876; Hookeriopsis incurva (Homsch.) Broth. in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 942. 1907. Hookeriopsis subincurva Thér., Mem. Soc. Cub. Hist. Nat. “Felipe Poey” 14: 369. 1940. Discussion. Thamniopsis incurva is unlikely to be confused with any other moss. Its broadly ovate to oblong leaves with all the upper marginal cells forming short, inflated, mostly bifid teeth and short upper laminal cells becoming longer below, combine to form a truly distinctive plant. It is unlike any other species of Thamniopsis in our area, but very much like (but probably not synonymous with) the African and Asian members of the genus, many of which are very Lepidopilum-like in aspect. The only other Hookeriopsis s.l. in our area with broadly rounded leaves is Thamniopsis cruegeriana. However, in that species only the stem leaves have a rounded apex, and they are almost entire rather than coarsely serrate.
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Distribution
Range. Guatemala to Panama, Venezuela to Chile (type locality) and Argentina, Brazil, Guyana, Trinidad; Cuba, Hispaniola (Dominican Republic), Puerto Rico; on rotting logs, in humid forests, mostly at 100-500 m, sometimes higher.
Guatemala Central America| Panama Central America| Venezuela South America| Chile South America| Argentina South America| Brazil South America| Guyana South America| Trinidad and Tobago South America| Cuba South America| Dominican Republic South America| Puerto Rico South America|