Hygroamblystegium tenax (Hedw.) Jenn.

  • Authority

    Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)

  • Family

    Amblystegiaceae

  • Scientific Name

    Hygroamblystegium tenax (Hedw.) Jenn.

  • Description

    Species Description - Plants rather small, usually ± soft, dark- or yellow-green. Stem leaves erect or ± spreading often ± incurved when dry, 0.7-1.5 mm long, ovate to ovate-lanceolate, gradually acute or acuminate; costa yellowish, fairly strong, disappearing near the apex, usually flexuose above; upper cells oblongrhombic, about 2-3:1; cells at the insertion somewhat enlarged in 2-3 rows, often yellowish, a few alar cells occasionally somewhat enlarged. Branch leaves ± incurved when dry, oblong-lanceolate or occasionally ovate, acute or acuminate and blunt-tipped, 0.5-0.8 mm long. Setae 10-25 mm long; capsules 2-2.5 (rarely 3.5) mm long. Spores 13-18 µm, finely papillose.

  • Discussion

    Fig. 663

    H. tenax (Hedw.) Jenn., Man. Mosses W. Penn. 227. 1913.

    Hypnum tenaxHedw., Sp. Muse 277. 1801.

    H. orthocladumP.-Beauv., Prodr. Aetheog. 67. 1805.

    H. irriguum Hook. & Wils. ex Wils., Bryol. Brit. 361. 1855.

    Hygroamblystegium irriguum (Hook. & Wils. ex Wils.) Loeske, Moosfl. Harz. 299. 1905.

    H. orthocladum (P.-Beauv.) Loeske, Stud. Morph. Syst. Laubm. 192. 1910.

    These plants can generally be distinguished from Amblystegium varium by growth in wetter places and leaves incurved when dry and more stoutly costate. The costa of A. varium is rarely more than 35 µm wide, whereas that of Hygroamblystegium tenax is generaUy 35-75 µm wide. If it were not for the other species of Hygroamblystegium, much stouter with much thicker and longer costae, one could conveniently abandon the genus. However, it generally serves a useful purpose, although a close relationship to Amblystegium can scarcely be denied.

  • Distribution

    On wet, calcareous and non-calcareous rocks in or beside brooks; Baja California, Mexico, Michoacan, Oaxaca, Puebla, Tamaulipas.—Mexico; Newfoundland to the Great Lakes region, west to Kansas and south to North Carolina, Alabama, and Texas; widespread from the Pacific Northwest to Wyoming and south to Arizona; Macaronesia, North Africa, Europe, and the Caucasus; across Asia to Japan.

    Mexico North America| Canada North America| United States of America North America| Europe| Armenia Europe| Azerbaijan Asia| Georgia Asia| Iran Asia| Russia Asia| Turkey Asia| Asia| Algeria Africa| Egypt Africa| Tunisia Africa| Libya Africa| Morocco Africa| Sudan Africa|