Orthotrichum pycnophyllum Schimp.

  • Authority

    Buck, William R. 1987. Bryostephane Steereana: A Collection of Bryological Papers Presented to William Campbell Steere On The Occasion of His 80th Birthday. Mem. New York Bot. Gard. 45: 1-749.

  • Family

    Orthotrichaceae

  • Scientific Name

    Orthotrichum pycnophyllum Schimp.

  • Description

    Species Description - Plants in loose or dense tufts or single among other bryophytes, yellowish green to olive-green above, brown below, to 3 cm tall; rhizoids present at bases of stems only. Leaves spreading or recurved when moist, erect and somewhat flexuose when dry, sometimes slightly undulate, from ovate bases acute or acuminate, 2.8-3.5 x 0.5-1.0 mm ; costa ending shortly below the apex; margins entire, revolute to recurved at least in the central part, sometimes undulate near apex; basal leaf cells 25-50 x 9-12 µm, elongate, with thick nodose, porose walls; towards the margins ± quadrate and forming more or less distinct auricles; transitional zone with elongate, thick-walled, sinuose cells sometimes developed between typical basal and upper cells; upper cells 8-17 × 6-12 µm, isodiametric to elongate, rounded, thick-walled, in regular rows, densely set with low branched or single papillae to four per cell. Goniautoicous. Perichaetial leaves not differentiated. Capsules more or less exserted, cylindric, slightly or not constricted below the mouth and with eight furrows extending at least halfway down when dry; exothecial cells differentiated into eight bands in the upper half and with several rows of small, almost isodiametric cells below the mouth; stomata superficial, in central part of capsule, surrounded by a distinct ring of radiating cells; peristome double, preperistome not observed; exostome teeth 16, recurved or reflexed when dry, orange to red, with a dense cover of tall branched papillae on the outside, striated papillose on the inside; endostome segments 16, linear to narrowly lanceolate, not appendiculate, almost as tall as the exostome, paler, usually with every second tooth two cells wide, the other one cell wide, more openly papillose. Spores globose, 22-28(-36) µm, densely and evenly papillose, brown with green interior. Calyptrae conic-oblong, vdth fine sharp ridges, with few or many, more or less flexuose, papillose hairs. Vaginula strongly hairy. Total number of collections studied: 52.

  • Discussion

    Type: MEXICO. Oaxaca: Chinantla, Liebmann 69 (lectotype ny; isotypes bm, c).

    Orthotrichum epibryum DeNot., Mem, Reale Accad. Sci. Torino ser. 2, 18: 448. 1859. Type: COLOMBIA. Ad rivum Napi, Osculati s.n. (holotype RO; isotype S).

    Orthotrichum wagneri Lor., Moosstudien 162. 1864. Type: ECUADOR. Pichincha; 1859, Wagner s.n. (holotype M).

    Orthotrichum apiculatum Mitt., J. Linn, Soc, Bot. 12: 188. 1869, hom. illeg. Type: ECUADOR. Pichincha: Spruce 124 (holotype NY; isotype S).

    Orthotrichum rubescens Mitt., J. Linn. Soc, Bot. 12: 188. 1869. Type: ECUADOR. Andes Quitenses, Patate. Spruce s.n. (lectotype NY).

    Orthotrichum lorentzii C. Müll, Linnaea 42: 358. 1879. Type: ARGENTINA. Cuesta de Pinos, 1873, Lorentz s.n. (lectotype s; isotype H).

    Illustrations: Figures 144-155.

    Variation: Orthotrichum pycnophyllum is a very variable species. In particular the diflferent leaf apex shapes have led to the description of many new taxa. They vary from gradually acute to abruptly narrowed into apiculate, acute or acuminate points. The apical ceUs vary from almost isodiametric to narrowly elongate. The capsules of the South American specimens diflfer from their northem counterparts in being always exserted and striate at least in the upper half. The Argentinian plants vary more in leaf cell size than the more northem populations.

    Differentiation: For separation of O. pycnophyllum and O. pariatum see the latter, for distinction of var. pycnophyllum and var. verrucosum see the following description.

    Notes: Orthotrichum epibryum is conspecific with O. pycnophyllum. D e Notaris' drawings in the protologue show denticulate leaf apices (De Notaris, 1859). They are, however, only slightly erose-crenulate, as also stated in the text. Orthotrichum wagneri is compared with O. pycnophyllum and O. recurvans in its type description. It is said to diflfer from the former in the dry leaves being recurved, in capsule shape and calyptra. From O. recurvans it should be distinguished by short exserted, non-striate capsules, and larger size. Orthotrichum recurvans, however, is now considered a synonym of O. pycnophyllum (Vitt, 1973). The latter is a very variable taxon and the diflferences mentioned do not justify recognition of O. wagneri as a separate species.

    The type specimens of O. lorentzii only have a few mature sporophytes and the peristomes of these are more or less disintegrated. They have, however, contrary to what the protologue says, 16 endostome segments, instead of eight broad lanceolate ones with articulate apices. The leaves are fairly soft, lanceolate, with the margins narrowly recurved. In some leaves the upper cells are rather large, 12.5-19 x 11-17 µm, in others they fall within the variation of O. pycnophyllum. Orthotrichum apiculatum represents one ofthe extreme forms of O. pycnophyllum. The plants have most ofthe leaves abruptly contracted into somewhat curved apices and the extreme apical cells are often more elongate than in typical O. pycnophyllum. Transitional forms were, however, observed and O. apiculatum is therefore included in O. pycnophyllum. The peristome has 16 exostome teeth and endostome segments, which also indicates a strong relationship between the two.

    Among the South American specimens no group could be sorted out matching the newly described species O. hortonae Vitt known from Mexico and Guatemala (Vitt, 1979).

  • Distribution

    Distribution: Argentina, Bolivia, Colombia,

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