Arthonia reniformis (Pers.) Nyl.

Flora, 59: 330, 1867. Basionym: Opegrapha reniformis Pers. - Ann. Bot. (Usteri), 7: 31, tab. II, fig. C, 1794.
Synonyms: Arthonia gyrosa Ach.; Arthonia obscura Ach.; Arthonia reniformis (Pers.) Röhl.; Arthonia vulgaris var. obscura (Ach.) Schaer.; Naevia gyrosa (Ach.) A. Massal.
Distribution: N - Ven, TAA. C - Sar (TSB 31118). S - Cal (Puntillo 1996), Si (TSB 17252).
Description: Thallus crustose, episubstratic, thin, mostly continuous, strongly rugose, sometimes somewhat shiny, whitish to greenish grey. Apothecia arthonioid, black, round to irregularly lobed, 0.5-1(-1.5) mm across, often crowded and confluent, with a flat to slightly convex, epruinose disc, the central parts often degrading. Epithecium brown-black, 10-25 µm high; hymenium colourless to pale reddish brown, 25-50 µm high, I+ reddish orange; paraphysoids thin, coherent, the apical cells without a dark cap; hypothecium colourless to pale yellowish brown. Asci 8-spored, broadly clavate, semi-fissitunicate, with a large apical dome and a distinct ocular chamber, Arthonia-type. Ascospores 5-6-septate, hyaline, narrowly ellipsoid, pointed at one end, 13-20 x 4-6 µm. Pycnidia black, semi-immersed in the thallus. Conidia curved, 5-7 x 1.2-1.4 , to reddish brown. Photobiont trentepohlioid. Spot tests: thallus K- or K+ yellowish brown, C-, KC-, P-. Chemistry: without lichen substances.
Note: a mild-temperate species of smooth bark, especially of Carpinus, more rarely of Fagus and Corylus, in humid deciduous woodlands. It is included in the Italian red list of epiphytic lichens as “Vulnerable” (Nascimbene & al. 2013c).
Growth form: Crustose
Substrata: bark
Photobiont: Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: extremely rare
Submediterranean belt: extremely rare
Padanian area: absent
Humid submediterranean belt: very rare
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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P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (31118)
2003/03/11


Redinger, K. (1938) Arthoniaceae, Graphidaceae . In Kryptogamen-Flora von Deutschland, Österreich und der Schweiz. Band 9, 2 Abt., Part 1 (G. L. Rabenhorst, ed.): 181–404. Leipzig: Borntraeger