Lobothallia cheresina var. justii (Servít)

Provisionally placed here, ICN Art. 36.1b.. Basionym: Lecanora justii Servít - Feddes Rep., 38: 65, 1935.
Synonyms: Aspicilia cheresina var. justii (Servít) Clauzade & Cl. Roux
Distribution: C - Umb (Genovesi & Ravera 2001, Ravera & al. 2006), Laz (Nimis & Tretiach 2004), Abr (Nimis & Tretiach 1999), Sar.
Description: Thallus crustose, episubstratic, continuous to cracked at the periphery, areolate in central parts, very well delimited (sometimes by a black prothallus), forming orbicular patches on the thalli of Circinaria calcarea; the marginal part of the thallus is often radially cracked, giving it an almost placodioid appearance. Areoles angular, flat, smooth, white to pale grey. Apothecia lecanorine-aspicilioid, 0.2-1 mm across, irregular in outline, from round to elongate or angular, immersed in the areoles, with a black, often grey-pruinose, concave to flat, smooth disc, and a very slightly raised thalline margin. Epithecium greenish brown; hymenium colourless; paraphyses more or less branched and anastomosing; hypothecium colourless, subtended by a continuous algal layer. Asci (6-)8-spored, clavate, the thin outer coat K/I+ blue, the wall and apical dome K/I-, Lecanora-type. Ascospores 1-celled, hyaline, broadly ellipsoid, 8-14 x 5-10 μm, 1-2 seriate in the asci. Pycnidia immersed, black, the wall colourless in sections except around the ostiole. Conidia bacilliform, 4-5 x c. 1 μm. Photobiont chlorococcoid. Spot tests: thallus K+ yellow, then slowly red-brown, C-, KC-, P+ yellow, UV-. Chemistry: stictic acid (major), norstictic acid (minor).
Note: a southern European and Mediterranean-montane, very characteristic but often overlooked lichen described from Egypt; it is found on calcareous rocks, starting the life-cycle on Circinaria calcarea and related species; this is the chemotype with with stictic acid as the major compound.
Growth form: Crustose placodiomorph
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
paras Circinaria calcarea s.lat.

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

Pier Luigi Nimis - CC BY-SA 4.0
TSB 26363

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (32479)