Phyllodon truncatulus W. R. Buck 1987

Phyllodon truncatulus

Phyllodon truncatulus (Müll. Hal.) W. R. Buck, Mem. New York Bot. Gard. 45: 521. 1987. Hypnum truncatulum Müll. Hal., Syn. Musc. Frond. 2: 263. 1851; Ectropothecium truncatulum (Müll. Hal.) Mitt., J. Linn. Soc., Bot. 12: 517. 1869; Trichosteleum truncatulum (Müll. Hal.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1876–77: 415. 1878; Glossadelphus truncatulus (Müll. Hal.) M. Fleisch., Musci Buitenzorg 4: 1352. 1923. Type: Peru. Pöppig (BM!).

Hookeriopsis cocoensis R. S. Williams, Bryologist 27: 40. 1924; Glossadelphus cocoensis (R. S. Williams) E. B. Bartram, Proc. Calif. Acad. Sci. IV, 21: 86. 1933. Type: Cocos Island, 1905–1906, A. Stewart 1432a (holotype: NY!).

Glossadelphus longisetus E. B. Bartram, Contr. U.S. Natl. Herb. 26(3): 109. 1928. Type: Costa Rica. Limón: vicinity of Guapiles, 300–500 m, 12–13 Mar 1924, Standley 37280 (holotype: FH!; isotype: US!).

Plants somewhat small, in dull, ± stiff, flat mats, green to yellow-green. Stems to ˜3 cm, creeping, elongate, subpinnately branched, the branches numerous, elongate, complanate-foliate; stems in cross section with 2–3 rows of small thick-walled cells surrounding abruptly larger thin-walled cells, central strand of small, very thin-walled cells; pseudoparaphyllia foliose; axillary hairs consisting of 1 short, brown basal cell and 2 elongate, hyaline distal cells. Stem and branch leaves similar but dorsal and ventral leaves differentiated from lateral leaves, 0.75–1.0 mm long, complanate, erect- to wide-spreading, often asymmetric, broadly ligulate, dorsal and ventral leaves narrower than lateral leaves, broadly rounded to emarginate, lateral leaves very concave; margins sharply serrate above, the teeth bifid, serrulate below, plane; costa short and double or absent; cells linear-flexuose, prorulose and/or seriately papillose, the papillae lower in basal half of leaf, thin-walled; alar cells scarcely differentiated, with a few subquadrate, concolorous cells in basal angles and across the insertion. Asexual propagula none. Synoicous. Perichaetial leaves 0.6–1.25 mm long, ovate to oblong-ovate, obtuse to short-acuminate; margins singly to doubly serrate above, entire below, plane; costa none; cells linear-flexuose, spiculose, the “papillae” to 30 μm tall, thick-walled, shorter and smooth toward the insertion; alar cells not differentiated. Setae 1.5–2.5 cm long, elongate, smooth, reddish; capsules ˜1.25 mm long, inclined, arcuate, asymmetric, ovoid; exothecial cells oval to short-rectangular, firm-walled, not collenchymatous; annulus of 1–2 rows of thick-walled cells; operculum ˜0.8 mm long, high-conic; exostome teeth yellow-brown, shouldered, bordered, on the front surface cross-striolate below, coarsely papillose above, trabeculate at back; endostome yellowish, with a high, smooth basal membrane, segments finely papillose, keeled, perforate, nearly as long as the exostome, cilia finely papillose, single, broad, 2–3-seriate below, sometimes split in two above. Spores 13–17 μm in diameter, spherical, finely papillose. Calyptrae cucullate, naked, smooth, falling early.

Distribution and ecology: Costa Rica, Panama, Colombia, Ecuador, Peru, Brazil, French Guiana, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico, and St. Vincent; growing mostly on moist rocks but also on tree trunks, in humid forests, at 200–600(–1200) m.

Illustrations in publications: Fig. 174 in Florschütz-de-Waard and Veling (1996: 455); Pl. 129 in Buck (1998: 327); Fig. 142 in Buck (2003: 160).

Discussion: Phyllodon truncatulus is an extraordinary species not likely to be confused with any other due to the ligulate leaves with broadly rounded apices and strongly prorulose and/or papillose cells. The marginal bifid serrations are particularly striking. The species seems close to the Angolan P. truncatus (Welw. & Duby) W. R. Buck but differs, among other features, by the smooth rather than strongly roughened seta.

Selected specimens examined: COSTA RICA. Cartago: Vicinity of Pejivalle, 900 m, Standley & Valerio 47141 (NY). Guanacaste: Slopes of Miravalles, above Bijaagua, 1500 m, Gomez et al. 19105 (MO, NY). Puntarenas: Near Monteverde, 1373 m, 20 Feb 1972, W. James s.n. (NY). PANAMA. Panamá: 5.5 km N of Cerro Azul, 763 m, Tyson et al. 2483 (NY). JAMAICA. Portland Parish: Hardwar Gap Falls, ˜1220 m, Welch 17594A (NY). St. Andrew Parish: Trail from Hardwar Gap to Mt. Caledonia (Old England Trail),1.4–2.8 km NNW of Hardwar Gap, 18°06'N, 76°44'W, 1342–1403 m, Crosby 3210 (DUKE, NY). St. Thomas Parish: Corn Puss Gap and vicinity, ˜12.4 km N of Bath on trail to Port Antonio, 18°00'N, 76°21'W, 550 m, Buck 5542, 5586 (NY). DOMINICAN REPUBLIC. La Vega: Vicinity of Piedra Blanca, near Goodrich Rubber grove, 200–500 m, Allard 18812 (NY). ST. VINCENT. Below 305 m, Smith 1490a (NY). BRAZIL. Amazonas: Along the Rio Negro, slopes and summit of Serra Curicuriari, from Igarapé Arabú of the Rio Curicuriari to the summit, 0°20'S, 66°50'W, 450 m, Buck 2477 (INPA, NY). Mato Grosso: Chapada dos Guimaraes, Wasserfall Véu da Neuva, 500 m, Schäfer-Verwimp 8626 (NY). Minas Gerais: Mpio. São Roque de Minas, Parque Nacional da Serra da Canastra, Caachoeira Casca D’Anta, 20°18'S, 46°31'W, 1000 m, Vital & Buck 11936 (NY, SP). Rio de Janeiro: Parque Nacional do Itatiaia, along trail to Véu de Noiva and Itaporani, ˜13.5 km N of town of Itatiaia, 22°25'S, 44°36'W, 1100 m, Vital & Buck 19976 (NY, SP). Santa Catarina: Blumenau, Park Floresta Negra, 200 m, Schäfer-Verwimp 8240 (NY). São Paulo: São Paulo, Pico do Jaragua, 810 m, Schäfer-Verwimp & Verwimp 9026 (NY). COLOMBIA. Antioquia: Mpio. Santo Domingo, Corregimiento de Santiago, sector “La Negra,” ˜6 km O [W] de Santiago, 06°30'N, 75°10'W, 1100–1165 m, Churchill et al. 14851 (NY). Caquetá: Transecto Neiva–San Vicente del Caguán, Quebrada Chorreras, entre Guayabel y Los Andes, 02°30–33'N, 74°30'–75'00W, 1300 m, Churchill & Betancur 16864-B (NY). Magdalena: Parque Nacional de la Sierra Nevada de Santa Marta, Vertiente oriental del Río Buritaca, 700 m, Griffin et al. 1137 (FLAS, NY). ECUADOR. Napo: Añangu, S shore of Río Napo, ˜75 km E of Puerto Francisco de Orellana, “Coca,” 0°32'S, 76°23'W, 245–325 m, Churchill & Sastre-De-Jesús 13820 (AAU, NY). Pastaza: ˜5 km SE of Puyo on road to Macas, 01°31'S, 77°55'W, 1000 m, Churchill & Sastre-De-Jesús 13688 (AAU, NY). FRENCH GUIANA. St-Laurent-du-Maroni: Canton de Maripasoula, Commune de Saül, ˜6 km N of Saül along road to Bélizon, vicinity of Eaux Claires, 03°37'N, 53°12'W, 200 m, Buck 18508 (NY). PERU. San Martín: Prov. Lamas, Strasse Yurimaguas–Tarapoto, Km 112, 900 m, Frahm et al. 1472 (B, NY).