Taxiphyllum ligulaefolium W. R. Buck 1990

Taxiphyllum ligulaefolium

Taxiphyllum ligulaefolium (E. B. Bartram) W. R. Buck, Trop. Bryol. 2: 42. 1990. Glossadelphus ligulaefolius E. B. Bartram, Bryologist 49: 123. 1946. Type: Guatemala, Dept. Izabal, jungle between Escobas and waterfall, across bay from Puerto Barrios, 20–25 m, Steyermark 39846 (holotype: FH!).

Taxiphyllum gallorum W. R. Buck, Brittonia 36 (2): 178. 1984b. Type: Jamaica, Trelawny Parish, Cockpit Co., just N of Wilson’s Run, 5.8 mi. N of bridge at Troy, 500 m, 18°16'N, 77°40'W, Buck 5888 (holotype: NY!).

Plants in thin mats, glossy, yellowish green. Stems to 1 cm long, 2–3 mm wide, complanate, simple or irregularly branched. Leaves 0.9–2.5 mm long, 0.2–0.3 mm wide, rigid, close, erect-spreading, complanate, slightly concave at base, smooth, linear-oblong, symmetric, abruptly acute to subobtuse, ending in a single or a few terminal cells; margins plane, sometimes erect below, serrate to serrulate above, serrulate to subentire below; costa usually weak, short and double, sometimes lacking; median cells 47–94 × 4–5 µm, smooth or prorulose at upper ends on

dorsal surface; alar cells usually differentiated, quadrate to short-rectangular, 2–4 extending up margins. Sex organs and sporophytes unknown.

Distribution and ecology: Very rare or seldom collected; known only from Mexico, Guatemala, Belize, and Jamaica (Figure 33); occurring on limestone in humid forests, sometimes near waterfalls, up to 1158 m.

Discussion: Taxiphyllum ligulaefolium is a very distinctive species that is easily recognized by the leaves that are close, erect-spreading, linear-oblong, with abruptly acute to subobtuse apices usually ending in a single terminal cell, the serrate to serrulate margins, the narrow median leaf cells, and the small region of differentiated alar cells, 2–4 quadrate to short-rectangular cells on margins.

It is of interest to note that the serrations on the margins near the leaf apex of the only Mexican plant (Puebla, Santos 3694 MICH) known from the country thus far are described as simple in the Glossadelphus key (Crum, 1994a: 1002) and description (Crum, 1994a: 1003), which we consider a synonym of this species (as G. ligulaefolius E. B. Bartram), but illustrated as minutely bifid (Crum, 1994a: 1004, fig. 747b). However, no such minute bifid serrations were observed in any of the Mexican plants from the same collection (seen at FH but not at MICH) or any of the plants from elsewhere that the authors studied.

This species can be confused with a Pseudotaxiphyllum because of the few foliose pseudoparaphyllia present on its stems.

Specimens examined: MEXICO. Puebla: Near summit of El Cerro de Cuhuatepetl, Tehuacan, 945–1158 m, Santos 3694 (FH). GUATEMALA. Known only from type locality. BELIZE. Toledo, Columbia River Forest Reserve, Union Camp, 680 m, 16°23'N, 89°08'W, Allen 18552 (MO). JAMAICA. Same locality as type of Taxiphyllum gallorum, Crosby 13875 (NY).

Taxiphyllum ligulaefolium là một loài Rêu trong họ Hypnaceae. Loài này được (E.B. Bartram) W.R. Buck miêu tả khoa học đầu tiên năm 1990.