Sematophyllum aberrans E. B. Bartram 1957

Sematophyllum aberrans

Sematophyllum aberrans (Broth.) Bartr., Ark. Bot. ser. 2, 4:41, 1957.

Rhaphidostegium aberrans Broth. in Skottsb., Nat. Hist. Juan Fernandez 2:441, 1924. [Original material: Quebrada del Monte Maderugo, Mas a Tierra, coll. C. & I. Skottsberg n. 377 (lectotype, present designation; S!).]

Rhaphidostegium caespitosoides Broth. in Skottsb., Nat. Hist. Juan Fernandez 2:442, 1924. [Original material: Quebrada de las Casas, ca. 200 m, Mas Afuera, coll. C. & I. Skottsberg n. 493 (lectotype, present designation; S!).]

Small, pale yellowish green, prostrate, frequently but irregularly branched, sparingly radiculose plants, with main stems 1–2 cm long, branches 2–4 mm long. Leaves laxly spreading, slightly secund, concave, to ca. 1.5–1.7 mm long, 0.3–0.5 mm wide, narrowly ovate-lanceolate to linear-lanceolate, tapering to a long, slender tip; margins slightly recurved below, slightly serrulate above; median cells linear, 6–7 μm wide, 60–80 μm long, walls slightly thickened and nearly as wide as the very narrow lumens; upper cells scarcely shortened, those in the very slender apex almost as long; inner basal cells yellow, to 10 μm wide, 40 μm long, thick-walled and porose; alar cells with 1 series of 3–4 very enlarged, rectangular, thin-walled, yellowish cells, ca. 20 μm wide, to 60 μm long; supraalar cells few, short-rhomboidal to subquadrate, ca. 25 μm long. Autoicous. Perichaetial leaves to 1.5 mm long, longest having plane, rather broad, tapering, subulate tips, becoming rather obtusely pointed at apex with distinct, small, apical teeth and shorter apical cells, cells ca. 25 μm long. Setae 7–10 mm long, red, smooth. Capsule horizontal to pendant; urn ca. 0.7 mm long, very slightly pustulose at base, broadly oval and constricted below mouth when dry. Spores 10–15 μm in diameter when very young, 15–18 μm in diameter when mature, very minutely papillose.

MAS AFUERA: Q. Casas, Sk. 371, 493 (lectotype of Rhaphidostegium caespitosoides), 494, 495 (all S); Q. Mono, 475 m, Sk. 388 (S); between Sanchez and Toltén, 515 m, Sk. 390 (S); Q. Blindado, 440 m, Sk. 489 (S); Cordón Barril, Sk. 498 (S); Q. Chozas, Sk. M111 (S).

MAS A TIERRA: Q. Monte Maderugo, Sk. 377 (type, S); Plazoleta in V. Anson, ca. 260 m, Sk. 379 (S); Q. Juanango, ca. 250 m, Sk. 384 (S); Centinela, ca. 530 m, Sk. 385, 389 (S); Salsipuedes, 660 m, Sk. 386 (S); Q. Gutierrez, ca. 300 m, Sk. 387 (S); Q. Frances, slope of Cordón Chifladores, K. 80 (S); Cerro Damajuana, K. M326 (S); El Yunque, near summit, ca. 900 m, K. M343, M347 (S); trail to Portezuelo de Villagra, 1400–1800 ft, H. & E. 85.

As presently known the species is endemic to Juan Fernandez. Brotherus (1924) placed his Rhaphidostegium aberrans and R. caespitosoides in different subgenera but there seems to be no specific difference.

Sematophyllum aberrans là một loài Rêu trong họ Sematophyllaceae. Loài này được (Broth.) E.B. Bartram miêu tả khoa học đầu tiên năm 1957.