Didymodon rigidulus Hedw.

  • 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 rigidulus Hedw.

  • Description

    Species Description - Plants green to blackish-green above, light- to dark-brown below. Stems rarely branched (irregularly), mostly 10-20 mm high. Propagula often present, on rhizoids and in leaf axils, green or brown, ovoid to elhpsoidal, mostly consisting of 3-8 cells. Leaves when dry erect or weakly spreading, when moist somewhat to widely spreading, concave, 0.8-1.9(-3) mm long, ovate- to long-lanceolate, obtuse to acuminate, occasionally thick and fleshy at the apex (which occasionally bears rhizoids), the base scarcely differentiated to ovate or oblong, not or shortly decurrent; margins usually narrowly recurved in the lower 1/2-3/4, entire, with cells sometimes bistratose, wholly or in patches, above the midleaf; costa often flexuose, percurrent to long-excurrent as a terete, fleshy, sharp subula, covered on both surfaces above the leaf middle by quadrate, usually smooth cells (2-6 rows wide at midleaf), with ventral stereids sometimes lacking and hydroids none; upper cells subquadrate to hexagonal, (5-)7-9(-12) µm, with papillae none or simple to bifid, 1-2 per cell on the dorsal surface or both surfaces, usually appearing centered, occasionally fused in longitudinal rows; basal cells not or weakly differentiated, quadrate to short-rectangular, 7—12(—36) µm wide and 1-4: 1, evenly thick-walled or occasionally thin-walled. Setae 7-17 mm long; capsules 1-2 mm long, long-elliptic to cylindric, occasionally ovoid, sometimes curved; operculum 0.4-0.9(-1.5) mm long, long-conic to conic-rostrate with cells in straight or ± counterclockwise- oblique rows; peristome of 16 rudimentary teeth or 32 filiform divisions, 180-740 µm long, yellow-brown or occasionally orange, straight or twisted 1.5 times, usually densely spiculose or occasionally granulose, the basal membrane low. Spores 9—12(—15) pm, smooth.

  • Discussion

    D. rigidulus Hedw., Sp. Muse. 104. 1801.

    Tortula acuta Brid., Muscol. Recent. Suppl. 1: 265. 1806.

    Barbula acuta (Brid.) Brid., Muscol. Recent. Suppl. 4: 96. 1819.

    B. teretiuscula Schimp. exC. Mull., Syn. Muscol. Frond. 1:614.1849.

    B. rigidula (Hedw.) Milde, Bryol. Siles. 118. 1863.

    B.flaccidiseta Lor., Moosstud. 161. 1864.

    Tortula rigidula (Hedw.) Lindb., Ofvers. Forh. Svenska Vetensk.- Akad. 21(4): 249. 1864.

    T. teretiuscula (Schimp. exC. Miill.) Mitt., J. Linn. Soc, Bot. 12:160. 1869.

    Didymodon mexicanus Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 172.1872.

    Trichostomum ramulosum Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 177.1872.

    Barbula gracilescens Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 178.1872.

    B. graciliformis Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 179. 1872.

    B. leptocarpa Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 179.1872.

    B. rigidulaBesch.,Mem. Soc. Sci. Nat. Cherbourg 16:180.1872, horn. illeg., non (Hedw.) Milde, 1863.

    B. erythropoda Schimp. ex Besch., Mem. Soc. Sci. Nat. Cherbourg 16: 180.1872.

    B. mobilis C. Mull., Linnaea 42: 482. 1879.

    B. bescherellei Sauerb. ex Jaeg., Ber. Thatigk. St. Gallischen Naturwiss. Ges. 1877-78: 409. 1880, nom. nov. for B. rigidula Besch.

    B. godmaniana C. Miill., Bull. Herb. Boissier 5: 193. 1897.

    B. strictidens C. Mull., Bull. Herb. Boissier 5: 193. 1897.

    B. lagunicola C. Mull., Bull. Herb. Boissier 5:194. 1897.

    Trichostomum mexicanum (Besch.) C. Miill., Gen. Muse. Frond. 420. 1900.

    Didymodon viridissimus Card., Rev. Bryol. 36: 82. 1909.

    D. pusillus Card., Rev. Bryol. 36: 82. 1909, horn, illeg., non Hedw. 1801.

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

    Barbula subteretiuscula Card., Rev. Bryol. 36: 85. 1909.

    B. altiseta Card., Rev. Bryol. 36: 85. 1909.

    B. bescherellei var. stenocarpa Card., Rev. Bryol 37: 126. 1910.

    B. heribaudii Card., Rev. Bryol. 40: 35.1913.

    B. bescherellei var. crassinervia Ther., Smithsonian Misc. Collect. 85(4): 17.1931.

    Didymodon godmanianus (C. Miill.) Bartr., Bryologist 49: 113.1946.

    Barbula acuta var. bescherellei (Sauerb. ex Jaeg.) Crum, Bryologist 72: 241. 1969.

    Didymodon acutus (Brid.) Saito, J. Hattori Bot. Lab. 39: 519. 1975.

  • Distribution

    On soil, gravel, acid and calcareous rock, and walls, in moist or dry habitats at 900-3600 m elev.; Baja California, Baja California Sur, Chiapas, Chihuahua, Coahuila, Distrito Federal, Durango, Hidalgo, Jalisco, Mexico, Michoacan, Morelos, Nuevo Leon, Oaxaca, Puebla, San Luis Potosi, Sonora, Tamaulipas, Tlaxcala, Veracruz, Zacatecas.—Nearly worldwide, in tropical latitudes at higher elevations.