Orthotrichum rupestre Schleich. ex Schwägr.
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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.
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Family
Orthotrichaceae
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Scientific Name
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Description
Species Description - Plants erect, in loose tufts, usually ca. 2.5 cm tall, if taller then lower parts of stems completely without leaves, yellowish green to olive-green to dark green above, dark brown to almost black below; rhizoids only present near the bases of stems. Leaves erect to slightly spreading when moist, erect and appressed when dry, ovate-lanceolate, long or short acute or acuminate, unistratose or with more or less extensive bistratose strands in the upper parts, 1.9-4.5 x 0.5-1 mm, apex acute, rounded acute or acuminate; costa strong, ending shortly below the apex; margins recurved nearly the entire length; basal leaf cells 25-90 × 5-11 µm, elongate, rectangular, thick-walled, usually nodose; marginal cells almost, quadrate with thinner walls; alar cells often differentiated, large, somewhat inflated and decurrent, brownish; upper leaf cells 6-15 x 5.5-6.5 µm, rounded, isodiametric or elongate with fairly thick walls, with 2-3 mostly branched, 3-6.5(-9) µm tall papillae per cell. Goniautoicous. Perichaetial leaves not markedly differentiated. Capsules immersed to emergent, oblong-ovoid, with eight furrows in the upper 1/2 to 2/3 when dry, only slightly constricted below the mouth; exothecial cells in upper parts of capsules differentiated into eight striae, below the mouth with a few rows of smaller cells; stomata superficial; peristome usually double, preperistome only rarely present; exostome teeth eight, splitting to 16 when old, erect or spreading when dry, hyaline, yellowish or pale brown, usually roughly papillose with developed ridges along the old cell walls, but sometimes finer papillose or even slightly striate to almost smooth; endostome segments eight, as tall or half as tall as the exostome, more or less roughly and densely papillose, sometimes smooth; operculum flat conic with short apiculus. Spores globose, 18-24(-28) µm, densely or more openly, regularly papillose, red-brown. Calyptrae conic-oblong or oblong, usually with many or few yellow or hyaline papillose hairs reaching over the top; hairs sometimes missing, sometimes developed into leaf-like structures.
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Discussion
Type: [AUSTRIA.] Pasterze, in Carinthiae alpibus, Schwdgrichen s.n. (lectotype g).
Orthotrichum nivale Spmce, J. Bot. 19: 11. 1881. Type: ECUADOR. Mt. El Altar, Spruce 127 (holotype ny; isotypes fh, h, s).
Orthotrichum lebrunii Besch., Bull. Soc. Bot. France 32: LXII. 1885. Type: ARGENTINA. Porto Gallegos, Chico, Lebrun s.n. (holotype pc, not seen; isotype NY).
Orthotrichum antarcticum Card., Rev. Bryol. 27: 43. 1900. Type: ANTARCTICA. Geriache Str., Racovitza 205c (holotype pc; isotypes BE, S).
Orthotrichum praeruptorum Herz., Biblioth. Bot. 88: 11. 1920. Type: BOLIVIA. Punta de San Miguel, Herzog 3443 (holotype JE; isotype H).
Orthotrichum subrupestre Ther., Revista Chilena Hist. Nat. 27:11.1923. Type: CHILE. San Cristobal, Bertho 103 (lectotype pc, chosen here; isotypes fh, s).
lllustrations: Figures 1-13.
Variation: The South American plants of O. rupestre are generally of a more erect and looser growth than specimens from the Northern Hemisphere. Further, they more commonly have well developed endostomes and no preperistomes. Two types of calyptrae occur. One is conic-oblong and strongly hairy, the other is oblong with few scattered hairs. This character, however, is not correlated with any other diflferences in morphology and due to the variability usually present in this taxon has been given no taxonomic value. In one specimen (Griffin, Lopez F. & Ruiz-Terán 389) the calyptra hairs are developed into leaf-like structures with well developed costae (Fig. 3). Another (Herzog 2601) had no hairs at all. The spores ofthe South American populations are fairly large, 18-24(-28) µm.. This indicates a relationship with other populations in the Southern Hemisphere. African plants have spore diameters measuring 24-27 µm and Australasian ones 20-26 µm, whereas the variation in North America is 13-21 µm. and in Europe 14-20 µm.
Differentiation: Orthotrichum rupestre is distinguished by the immersed to emergent capsules with erect to spreading exostome teeth when dry. For differences between it and O. anaglyptodon, O. latimarginatum, see those taxa.
Notes: Although the occurrence of O. rupestre in South America has been doubted until recently (Vitt, in press), many specimens seen during my studies belong to this taxon. The oldest collection dates back to 1858. It is the type specimen for O. nivale, initially referred to O. striatum Hedw. The first record of O. rupestre is Dusen's from 1903 followed by Herzog's from 1916. One of Herzog's collections (Herzog 3443) was later described as the new species O. praeruptorum. Also the type material of O. subrupestre had first been referred to O. rupestre (Theriot, 1921). The diflferences distinguishing these taxa are all minor. They are here regarded as conspecific with O. rupestre. For discussion of O. antarcticum see Ochyra (1986).
The plants referred to O. lebrunii by Matteri (1985) belong to the O. rupestre group. They are, however, not identical to the type specimen of O. lebrunii. They represent a form of O. rupestre with short leaves with revolute margins and rather tall mostly unbranched papillae. The plants are, however, not whitish like those of O. rupestre var. papillosum Lewinsky from N e w Zealand (cf. Lewinsky, 1984).
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Distribution
Distribution: Cosmopolitan; in South America in Argentina, Bolivia, Chile, Ecuador, Peru, Venezuela; also in Antarctica.
Argentina South America| Bolivia South America| Chile South America| Ecuador South America| Peru South America| Venezuela South America| Antarctica|