Stereocaulon rivulorum H. Magn.

Göteb. K. Vetensk. Samh. Handl., 30: 63, 1926.
Synonyms:
Distribution: N - Frl (TSB 14044), Lomb (Rivellini 1994, Rivellini & Valcuvia 1996), Piem, VA (Piervittori & Isocrono 1999).
Description: Primary thallus crustose, ephemeral, usually absent in mature individuals. Pseudopodetia ascending, terete, sparingly branched, sometimes with no distinct main axis, 1-2 cm tall, 0.5-1.2 mm thick, with a pinkish white tomentum, very brittle when dry, forming low lax tufts, with a solid cartilaginous axis of parallel hyphae surrounded by a lax medulla. Phyllocladia 0.2-1 mm, glaucous white with a bluish tinge, granular to slightly elongate, broader at apices, dispersed in groups along the pseudopodetia which are partly naked. Cephalodia infrequent, inconspicuous, violet brown, tubercular to slightly elongate, with a rough surface, containing Nostoc, located on the lower side of pseudopodetia. Apothecia frequent, terminal, 1-4 mm across, with a dark brown, convex disc and a thin, paler, finally excluded proper margin. Proper exciple brown in outer part, colourless within; epithecium brown, K-; hymenium colourless; paraphyses simple, slightly thickened above, with a dark cap; hypothecium colourless. Asci 8-spored, cylindrical-clavate, with a K/I+ blue outer layer and apical dome, and a central, K/I+ darker blue tube, Porpidia-type. Ascospores 3-septate, hyaline, fusiform, 20-30 x 4-5 µm. Pycnidia dark, immersed. Conidia cylindrical, straight or slightly curved, 6-8 x 1 µm. Main photobiont chlorococcoid. Spot tests: K+ yellow, C-, KC-, P- or P+ yellowish, UV- or UV+ blue-white. Chemistry: atranorin and variable amounts of lobaric acid.
Note: an arctic-alpine to boreal-montane lichen found on gravel and sand in snow-beds or on banks of streams near glaciers, sometimes on weakly calciferous schists; restricted to the Alps in Italy.
Growth form: Fruticose

Substrata: soil, terricolous mosses, and plant debris
Photobiont: green algae other than Trentepohlia (primary); cyanobacteria, filamentous (e.g. Nostoc, Scytonema) (secundary, e.g. in cephalodia)
Reproductive strategy: mainly sexual
Pioneer species

Commonnes-rarity: (info)

Alpine belt: rather rare
Subalpine belt: very rare
Oromediterranean belt: absent
Montane belt: very rare
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: absent
Dry mediterranean belt: absent

pH of the substrata:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model
Herbarium samples

Einar Timdal - Source: http://nhm2.uio.no/lav/web/index.html - CC BY-NC



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (15474)
2003/03/06


Frey E. 1933. Cladoniaceae (unter Ausschluß ded Gattung Cladonia) und Umbilicariaceae. In: Rabenhrst’s Kryptogamenflora von Deutschland, Österreich und der Schweiz. 15: 1-208.


Einar Timdal - Source: http://nhm2.uio.no/lav/web/index.html - CC BY-NC