Rhizocarpon superficiale (Schaer.) Malme

Svensk Bot. Tidskr., 8, 3: 282, 1914. Basionym: Lecidea superficialis Schaer. - Lich. Helv. Spicil.: 125, 1828.
Synonyms: Rhizocarpon crystalligenum Lynge; Rhizocarpon scabridum Räsänen; Rhizocarpon splendidum Malme
Distribution: N - Frl (Tretiach & Hafellner 2000), TAA, Lomb, Piem, VA (Piervittori & Isocrono 1999).
Description: Thallus crustose, areolate, bright yellow-green to whitish yellow, delimited by a black prothallus, forming 2-10 cm wide patches. Areoles round to angular, contiguous, the peripheral ones not markedly elongate, slightly to strongly convex, 0.3-25 mm wide, smooth or scabrous. Cortex poorly differentiated, 20-75 µm thick; medulla white, I-. Apothecia lecideine, black, round or angular, to 1.2(-2) mm across, with a flat to slightly convex, scabrid disc, and thin, often excluded proper margin. Proper exciple reddish brown in outer part, K+ reddish-violet; epithecium brown-black, blue-black or greenish brown, K+ reddish, with dark crystals; hymenium colourless to brownish, 60-100 µm high; apices of paraphysoids capitate; hypothecium brown, K-, 60-150 µm high. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores 1-septate, at first hyaline or pale green-brown, soon becoming dark green to brown, ellipsoid, 11-20 x 6-10 µm, halonate. Photobiont chlorococcoid. Spot tests: medulla K+ yellow turning red, rarely K+ persistently yellow, C-, KC-, P+ orange, rarely P+ brick red. Chemistry: rhizocarpic and norstictic acids or (rarely) stictic acid.
Note: a mainly arctic-alpine species found on exposed siliceous rocks with a short snow-cover, often very abundant in the nival belt of the Alps.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
paras Pleopsidium when young

Commonnes-rarity: (info)

Alpine belt: rather common
Subalpine belt: rare
Oromediterranean belt: absent
Montane belt: absent
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


P.L. Nimis CC BY-SA 04
TSB 24644



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (24644)
2001/12/10



Curtis Randall Björk – CC BY-SA 4.0
British Columbia, Thompson Plateau, near Cache Creek Date: 2013-02-03 On rock in sagebrush steppe



P.L. Nimis CC BY-SA 04
TSB 45512



P.L. Nimis CC BY-SA 04
TSB 45512



P.L. Nimis CC BY-SA 04
TSB 45512



P.L. Nimis CC BY-SA 04
TSB 45512



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (24644)
2001/12/10