Fissidens ornaticostatus H. Robinson 1974

Fissidens ornaticostatus

Fissidens ornaticostatus H. Robinson, Phytologia 29 (2): 116, 1974. [Original material: V. Colonial, Mas a Tierra, 435 m, coll. C. & I Skottsberg n. 26 (S!).]

Plants small with stems ca. 1 mm long. Leaves oblong-elliptical, 1.2 mm long, ca. 0.25 mm wide, acute without acumination; vaginant lamina ca. 0.6 mm long, acute, sometimes very short-acute, ending in from margin; dorsal lamina becoming decurrent at base; margin minutely serrulate, near base minutely dentate, not bordered; costa ending 5–6 cells before apex, 25–30 μm broad at base; with guide cells prominent and biseriate, 12–25 μm wide and 30–70 μm long, subbasal guide cells 75–130 μm long, cells on both surfaces of costa transparent and narrowly fusiform, 4–5 μm wide and 20–40 μm long; cells of lamina irregularly polygonal, 8–10 μm in diameter, smooth, cells near margin sometimes 6 μm in diameter, near costa 12 μm in diameter, near base of costa 18–40 μm long and 12 μm wide, submarginal cells of vaginant lamina mostly elongate to 35 μm long. Sporophyte unknown.

MAS A TIERRA: V. Colonial, Q. Seca, 455 m, Sk. 26 in part (holotype, S; isotype slide, US).

The species is represented by two stems from a mixture of F. leptochaete and F. crassicuspes. This one collection is the only one known for the two endemic species and the only known record for F. leptochaete from the islands. The single collection with two holotypes is ample evidence of the need for more collecting of the smaller species in Juan Fernandez.

The new species is most closely related to F. leptochaete but differs by the very prominent inner cells of the costa, the nonacuminate leaf tip, and the essentially nonpapillose leaf cells. Walls over the cell lumens are often a little thickened in the centers.

Fissidens ornaticostatus là một loài Rêu trong họ Fissidentaceae. Loài này được H. Rob. mô tả khoa học đầu tiên năm 1974.