Didymodon australasiae (Hook. & Grev.) R.H.Zander

  • Authority

    Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part One: Sphagnales to Bryales. Mem. New York Bot. Gard. 69 (1): 1-452.

  • Family

    Pottiaceae

  • Scientific Name

    Didymodon australasiae (Hook. & Grev.) R.H.Zander

  • Description

    Species Description - Plants green or blackish-green above, brown below. Stems often branched, u p to 6, rarely 15 mm high. Propagula occasional, on rhizoids between lower leaves, red-brown, spherical to ellipsoidal or irregular, consisting of 2-7 cells, up to 85 or 100 p m long. Leaves crowded, when dry spreading-incurved and twisted to erect-incurved, when moist spreading to spreading-recurved, broadly concave, l-2(-4) mm long, ovate-triangular to long-elliptic or long-lanceolate, acute, often ± cucullate at the tip, the base scarcely differentiated to noticeably ovate; margins plane or recurved at the middle or throughout the upper half; costa subpercurrent to short-excurrent, covered ventrally by quadrate, short-rectangular, or elongate cells and dorsally by elongate cells (those near the apex rarely quadrate), lacking a ventral stereid band, the dorsal band strong, weak, substereid or lacking, hydroids occasionally present; upper cells subquadrate to short-rectangular, 7-12 µm and 1-2:1, with papillae none or large, centered over the lumen, solid, simple, bifid or occasionally trifid, flattened and rounded, 1-4 on each surface; basal cells often sharply differentiated across the leaf or in median regions, quadrate to rectangular (often transversely so), up to 18(-23) µm wide and 2-5:1, with walls thin, hyaline, ± bulging, occasionally resorbed to form transverse slits in median portions, the basal marginal cells often narrow in 1 or more rows. Setae 7-10 m long; capsules 1-2 mm long, ovoid to ellipsoid-cylindric; operculum 0.7-1.2 mm long, longconic, often curved, with cell rows nearly straight or in 1 counterclockwise spiral turn; peristome consisting of 32 filiform divisions, about 600 µm long (or occasionally rudimentary), yellow, densely spiculose, nearly straight or twisted counterclockwise in 1/2 turn, with the basal membrane low or none. Spores 11-15 µm (possibly occasionally anisosporous and 6-9 and 12-15 µm) , weakly papillose.

  • Discussion

    D. australasiae (Hook. & Grev.) Zand., Phytologia 41: 21.1978.

    Tortula australasiae Hook. & Grev., Edinburgh J. Sci. 1: 301. 1824.

    Barbula australasiae (Hook. & Grev.) Brid., Bryol. Univ. 1: 828. 1827.

    B. graminicolorC Mull., Syn. Muse. Frond. 1: 611. 1849.

    Tortula graminicolor (C. Mull.) Mont, in Gay, Hist. Fis. Polit. Chil. Bot. 7: 156. 1850.

    Didymodon craspedophyllus Card., Rev. Bryol. 36: 81. 1909.

    D. torquescens Card., Rev. Bryol. 36: 83. 1909.

    Trichostomopsis crispifolia Card., Rev. Bryol. 36: 74. 1909.

    Didymodon diaphanobasis Card., Rev. Bryol. 37: 125. 1910.

    Husnotiella torquescens (Card.) Bartr., Bryologist 29: 45. 1926.

    Didymodon patentifoliusTher., Smithsonian Misc. Collect. 85(4): 15. 1931.

    Trichostomopsis brevifolia Bartr., Bryologist 34: 61. 1932.

    Astericium torquescens (Card.) Hilp., Beih. Bot. Centralbl. 50(2): 620. 1933.

    Trichostomopsis fayae Grout, Moss Fl. N. Amer. 1: 228. 1939.

    T. diaphanobasis (Card.) Grout, Moss Fl. N. Amer. 1: 228. 1939.

    T. australasiae (Hook. & Grev.) Robins., Phytologia 20: 187. 1970.

    Hydroids have been seen in Didymodon leaves only in this species and D . revolutus.

    The varieties listed below are distinctive in the extreme but completely intergrade with one another. The varietal designations given here are for the convenience of those who wish to recognize differences.

  • Distribution

    On soil and rock up to 3750 m elev.; Baja California, Baja California Sur, Chihuahua, Distrito Federal, Durango, Jalisco, Mexico, Michoacan, Oaxaca, Puebla, San Luis Potosi, Sonora, Veracruz, Zacatecas.—Mexico; Central and South America; North America; Europe and the Canary Islands; South Africa; Australasia.

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