Thermutis velutina (Ach.) Flot.

Linnaea, 23: 170, 1850. Basionym: Lichen velutinus Ach. - Lichenogr. Suec. Prodr.: 218, 1799.
Synonyms: Collema pannosum Hoffm.; Collema velutinum (Ach.) Ach.; Collema velutinum var. pannosum (Hoffm.) Rabenh.; Gonionema velutinum (Ach.) Nyl.
Distribution: N - Frl, Ven, TAA (Nascimbene & al. 2022), Lomb, Piem (Isocrono & al. 2004), Lig. C - Tosc. S - Camp (Aprile & al. 2003b), Cal (Puntillo 1996).
Description: Thallus minutely filamentous, forming up to 1 cm wide mats or flattened pillows on the rock, consisting of 10-12(-15) µm thick, simple or branched, brown-black, more or less ascending filaments without a central strand, each filament including a row of cells of Scytonema, whose gelatinous sheath is loosely infected with a few elongated hyphae, some of which usually produce haustoria that penetrate the cyanobacterial cells. Apothecia biatorine pycnoascocarps, 0.2-0.5 mm across, arising laterally on the filaments, dark reddish brown, with a concave, poriform disc, and a thick proper margin. Proper exciple of loosely intertwined hyphae, brown in outer part, colourless within; hymenium 100-150 µm high, colourless or brownish in upper part, K/I+ blue; paraphyses simple, thickened at apex; hypothecium colourless. Asci 8(-12)-spored, cylindrical, thin-walled, K/I+ blue. Ascospores 1-celled, hyaline, ellipsoid, 9-15 x 5-8 µm. Pycnidia arising laterally on the filaments, with a reddish brown ostiole. Conidia globose, formed terminally on the conidiophores, 1-2 μm wide. Photobiont cyanobacterial (Scytonema), the cells arranged in chains, 9-15 x 6-7 µm; photobiont trichomes with false branching, i.e. cell divisions exclusively anticlinal; when the photobiont trichome splits, the formerly connected ends start growing independently to form V-shaped branching (visible at least in younger parts of the thallus); trichomes often paired, but tips free and diverging. Spot tests: all negative. Chemistry: without lichen substances.
Note: on calciferous or base-, often mineral-rich siliceous rock, in sun-exposed seepage tracks with colonies of cyanobacteria, mostly in upland areas but usually below treeline.
Growth form: Fruticose filamentous
Substrata: rocks
Photobiont: cyanobacteria, filamentous (e.g. Nostoc, Scytonema)
Reproductive strategy: mainly sexual
On otherwise dry surfaces with short periods of water seepage after rain

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: very rare
Oromediterranean belt: extremely rare
Montane belt: extremely 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

Manuel Gil
Spain, Canary Islands, Lanzarote



Curtis Randall Björk – CC BY-SA 4.0
Clearwater Valley, British Columbia, Canada, on boulder at shore of white-water river
09.08.2015


Zahlbruckner A. 1926. Lichenes (Flechten). In: Engler A. (ed.): Die natürlichen Pflanzenfamilien. 2nd ed., vol 8, W. Engelmann, Leipzig, 270 pp.



Curtis Randall Björk – CC BY-SA 4.0
Clearwater Valley, British Columbia, Canada, on boulder at shore of white-water river
09.08.2015


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_T/Textes_T2/Thermutis_velutina.htm
France, 3/7/2011 - sur gabbro - session AFL en Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_T/Textes_T2/Thermutis_velutina.htm
France, 3/7/2011 - sur gabbro - session AFL en Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_T/Textes_T2/Thermutis_velutina.htm
France, 3/7/2011 - sur gabbro - session AFL en Corse


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_T/Textes_T2/Thermutis_velutina.htm
France, 3/7/2011 - sur gabbro - session AFL en Corse