Rhizocarpon hochstetteri (Körb.) Vain.

Acta Soc. Fauna Fl. Fenn., 53, 1: 280, 1922. Basionym: Catillaria hochstetteri Körb. - Parerga Lichenol.: 195, 1861.
Synonyms: Biatorina concreta auct. p.p. non (Ach.) Mudd; Buellia chlorospora (Nyl.) Hellb.; Buellia colludens Arnold; Buellia hochstetteri (Körb.) Mong.; Catillaria colludens (Arnold) Jatta; Catillaria concreta auct. p.p. non (Ach.) A. Massal.; Catocarpus applanatum (Fr.) Arnold; Catocarpus koerberi Stein; Lecidea applanata (Fr.) Leight.; Lecidea atroalba var. applanata Fr.; Lecidea atroalba var. chlorospora Nyl.; Lecidea colludens (Arnold) Nyl.; Lecidea hochstetteri var. colludens (Arnold) Vain.; Rhizocarpon applanatum (Fr.) Th. Fr.; Rhizocarpon concretum auct. p.p. non (Schaer.) Zahlbr. nec (Ach.) Elenkin; Rhizocarpon crenulatum H. Magn.; Rhizocarpon massalongoi sensu Malme non (Körb.)
Distribution: N - Frl, Ven, TAA (Nascimbene & al. 2022), Lomb, Piem (Isocrono & al. 2004, 2006), VA (Favero-Longo & al. 2006, Isocrono & al. 2008, Favero-Longo & Piervittori 2009), Emil (Fariselli & al. 2020). C - Tosc, Sar (Rizzi & al. 2011). S - Si (Nimis & al. 1996b, Brackel 2008b).
Description: Thallus crustose, episubstratic, grey-brown to red-brown, rimose or less frequently rimose-areolate, usually delimited by a black prothallus. Areoles flat to convex, 0.2-0.6(-1) mm wide. Medulla white, I-. Apothecia, lecideine, black, developing among the areoles, 0.6-1(-1.3) mm across, with a flat to slightly convex disc and a distinct, persistent, finally sometimes excluded proper margin. Proper exciple of radiating, dark brown hyphae; epithecium green to blue-black K-, N+ red; hymenium colourless, 95-150 µm high I+ blue; paraphysoids branched and anastomosing, 2.5-3 µm thick at mid-level, the apical cells to 3.5 µm, with a sharply delimited pigment cap; hypothecium dark brown. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores 1-septate, hyaline or sometimes pale grey-brown when overmature, (15-)21-25(-29) x 8-14 µm, halonate. Photobiont chlorococcoid, the cells 10-15(-18) µm in diam. Spot tests; medulla K- or rarely K+ yellow, C-, KC-, P- or rarely P+ orange. Chemistry: medulla with stictic acid, or without lichen substances.
Note: a widespread, probably northern holarctic lichen found on mineral-rich siliceous rocks, in seepage tracks and near creeks; most common in the Alps below the Alpine belt, rare in the mountains of Southern Italy.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: rather common
Oromediterranean belt: extremely rare
Montane belt: rather rare
Submediterranean belt: very rare
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


P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (8327)
2001/12/01



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (8327)
2001/12/01


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_R/Textes_R/Rhizocarpon_hochstetteri.htm
France, 4/3/2015 - Mont Cenis - Vanoise - Haute-Savoie