Atrichum muelleri Schimp.

  • 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

    Polytrichaceae

  • Scientific Name

    Atrichum muelleri Schimp.

  • Description

    Species Description - Plants in loose mfts, yellowish-green to dark-green. Stems slender, 1.5-2 cm high. Leaves straight and erect-spreading when moist, crisped and contorted when dry, upper leaves narrowly lanceolate, the lower ones lanceolate to elliptic, 4-5 mm long, 0.6-0.8 mm wide mid way between base and tip (up to 1.5 mm in lower leaves), narrowly bordered by linear cells, the border 6-10 µm wide, often ending short of the leaf apex; margin toothed in the upper 1/2 to 2/3, the teeth single or double; midrib toothed at back above; lamellae 4-6, confined to the nerve, spreading, 5-7 cells high; lamina typically concave, unistratose except for the border, plane or more typically undulate, with dorsal teeth in diagonal rows corresponding to the undulations; cells bulging-mammillose on the upper surface, smooth or more commonly papillose, the median cells ± isodiametric, (13-) 16-20 µm in diameter. Dioicous. Perigonial bracts forming rosettes, broadly triangular-ovate, unbordered. Perichaetial leaves longer and narrower than vegetative leaves. Setae yellowish-brown, 2 cm long, typically 1 per perichaetium; capsules brownish, cylindric, 5-6 mm long, 0.5-0.8 mm in diameter; operculum rostrate, the beak 1.5 mm long; peristome teeth 32. Calyptrae hispid to sparsely ciliate at the tip.

  • Discussion

    Fig. 799

    A. muelleri Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 206. 1872.

    A. schimperi Jaeg., Ber. Thatigk. St. Gallischen Naturwiss. Ges. 1873-74: 241. 1875.

    A. conterminum Card., Rev. Bryol. 37: 5. 1910.

    A. angustatum (Brid.) B.S.G. var. muelleri (Schimp. exBesch.) Bartr., J. Wash. Acad. Sci. 26: 15. 1936.

    This species differs from A. angustatum (Brid.) B.S.G. in having fewer, lower lamellae and larger leaf cells. Atrichum conterminum represents the extreme, and occasional forms approaching A. angustatum have been seen, but the majority of specimens fall outside the range of variation of A. angustatum as it occurs in Europe and North America.

    The name Atrichum angustatum var. rhystophyllum (based on Catharinea rhystophylla C. Müll.) is applied by several authors to Mexican material, but Nyholm (1971) recognized both Atrichum conterminum and A. angustatum from our area, while restricting A. rhystophyllum to Last Asian plants. The latter is common in Japan and varies but little. By contrast, Brothems (H-BR) equated A. rhystophyllum with A. henryi Salm. [=A. subserratum (Harv.) Mitt.], a very different species (Smith, 1976). The type of Catfiarinea rhystophylla, from China, has not been seen.

  • Distribution

    Chiapas, Distrito Federal, Durango, Jalisco, Michoacan, Oaxaca, Nayarit, Puebla, Tamaulipas, Veracruz.—Mexico; Central America; West Indies.

    Mexico North America| Central America| West Indies|