Taxiphyllum deplanatum Fleischer 1923

Taxiphyllum deplanatum

Taxiphyllum deplanatum (Schimp. ex Müll. Hal.) M. Fleisch., Musci Buitenzorg 4:1435. 1923. Hypnum deplanatum Schimp. ex Müll. Hal., Syn. Musc. Frond. 2: 260. 1851; Isopterygium deplanatum (Schimp. ex Müll. Hal.) Mitt., J. Linn. Soc., Bot. 12: 498. 1869; Plagiothecium deplanatum (Schimp. ex Müll. Hal.) Spruce, J. Bot. 18: 289. 1880. Type: United States, Sullivant,

Musci Allegh. 50 (lectotype: NY!, designated by Ireland, 1969); isolectotype: US!).

Isopterygium planissimum var. laxirete Thér., Smithsonian Misc. Collect. 85 (4): 43. 1931. Type: Mexico, Michoacán, vicinity of Morelia, Loma Santa María, 2000 m, Arséne 4877 (isotypes: FH!, US!).

Plagiothecium deplanatum f. ovatum Grout, Moss Fl. N. Amer. 3(3): 161. 1932. Type: Arizona, Pima Co., Santa Catalina Mts., Mt. Lemmon, Upper Sabino Canyon, 2743 m, Bartram, Mosses S. Arizona 161 (isotypes: CANM!, DUKE!, NY!, US!, WTU!).

Plants in thin to dense mats, glossy, light green to yellow-green. Stems to 2.5 cm long, 1–3 mm wide, complanate-foliate, simple or irregularly branched. Leaves 1.0–2.5 mm long, 0.4–1.0 mm wide, flaccid, usually crowded, imbricate, erect- to wide-spreading, somewhat concave or flat, smooth, ovate to ovate-lanceolate, symmetric to somewhat asymmetric, acute or acuminate, somewhat contorted when dry; margins plane, serrate to serrulate above, serrulate below; costa very short and double or lacking; median cells 47–136 × 5–9 µm, smooth; alar cells strongly differentiated, quadrate to short-rectangular, in 1 to several rows with 3–9 cells in the marginal row. Sex organs and sporophytes not seen on Latin American plants. North American plants reported (Ireland, In press b) to be dioicous; perigonia unknown; perichaetia small, numerous, the bracts lanceolate to ovate-lanceolate, acuminate. Setae 0.7–1.0 cm long, yellowish brown to red, flexuose; capsules 0.8–1.5 mm long, cernuous, straight or arcuate, yellowish brown to light brown, oblong or ovoid, contracted below mouth and tapered to a wrinkled neck when dry; operculum 0.3–0.5 mm, obliquely rostrate; annulus present, persistent. Spores 11–13 µm in diameter.

Distribution and ecology: Rare or seldom collected; Mexico and Honduras (Figure 33); also in eastern and southwestern North America; on shaded soil or limestone boulders and cliffs, sometimes on bases of trees and exposed tree roots, at 1000–2600 m.

Discussion: Taxiphyllum deplanatum is recognized by the flaccid, light to yellow-green, complanate-foliate plants, the imbricate, erect to wide-spreading, slightly concave or flat, ovate to ovate-lanceolate, acute or acuminate leaves with plane margins, and the noticeably differentiated alar regions of 1 to several rows of quadrate to short-rectangular cells with 3–9 differentiated cells in the marginal rows.

The Latin American plants of T. deplanatum are noticeably different from their North American counterparts in that the leaves are more distant, wide-spreading and they are somewhat contorted when dry. Microscopically, the plants were observed to be similar to the North American ones.

Specimens examined: MEXICO. Durango: ˜14.5 km W of La Ciudad, 2637 m, Bowers et al. 5083c (CANM, TENN). Hidalgo: Above Tianguistengo, 3.2 km from Zacualtipan, 2100 m, Sharp et al. 1825a (CANM, TENN), 1837 (CANM, F, MEXU, TENN). Morelos: ˜11 km above Cuernavaca, 2200 m, Düll 2/276 (MICH). San Luis Potosí: Just E of San Francisco, ˜45 km E of San Luis Potosí at K[m]-218 along Hwy. 70, 4260 m, Magill 2609 (MO, NY). Tamaulipas: Edge of Casa de Piedra, near Rancho del Cielo above Gómez Farias, Sharp 8728b (TENN); trail to Indian Spring, Rancho del Cielo above Gómez Farias, 1100–1200 m, Iwatsuki & Sharp 4845 (TENN). Veracruz: Txolo Falls,

near Jalapa, 1006 m, Sharp 3939 (MICH, TENN). HONDURAS. Comayagua: Vicinity of Siguatepeque, ˜1050 m, Standley & Chacón 6151 (F, FH).

Taxiphyllum deplanatum là một loài Rêu trong họ Hypnaceae. Loài này được (Bruch & Schimp. ex Sull.) M. Fleisch. miêu tả khoa học đầu tiên năm 1923.