Lathagrium latzelii (Zahlbr.) Otálora, P.M. Jørg. & Wedin

Fungal Divers. (online version), 64: 287, 2013. Basionym: Collema latzelii Zahlbr. - Österr. bot. Z., 59: 493, 1909.
Distribution: N - Emil (Valcuvia & Delucchi 2001, Fariselli & al. 2020). C - Sar. S - Si (Nimis & al. 1994).
Description: Thallus foliose, homoiomerous, gelatinous when wet, dark olive-green to black, rather firmly attached, deeply lobed, forming orbicular to irregular rosettes 15-60 mm in diam. Lobes 1-3(-5) mm wide, 50-120(-200) μm when wet, radiating, repeatedly branched, contiguous or often overlapping, with ascending, undulate not swollen margins, sometimes with globose to flattened isidia. Lower surface smooth, paler than upper surface. Apothecia lecanorine, 0.3-0.8(-1) mm across, sessile, strongly constricted at base and sometimes substipitate, with a concave to flat, brown disc, and a smooth thalline margin. Proper exciple euparaplectenchymatous, 15-40 μm wide laterally, (25-)40-70 μm wide at base; epithecium brown; hymenium colourless; paraphyses 1.5-2 μm thick at base, the apical cells swollen; hypothecium colourless. Asci 8-spored, narrowly clavate, the apex thick, with a I+ blue apical dome and a I+ blue annulus projecting downwardly. Ascospores submuriform, with 4-6 cells visible in optical view, hyaline, subglobose or cuboid, (12-)16-26 x 8-13 μm. Pycnidia frequent, marginal or laminal. Conidia bacilliform, thickened at apices, 4.5-5 x c. 1.5 μm. Photobiont cyanobacterial (Nostoc, in long chains). Spot tests: all negative. Chemistry: without lichen substances.
Note: a mild-temperate species found on steeply inclined seepage tracks of calciferous rocks, sometimes of serpentine, usually at low elevations; overlooked, perhaps more widespread in southern Italy, but certainly not common.
Growth form: Foliose, narrow lobed
Substrata: rocks
Photobiont: cyanobacteria, filamentous (e.g. Nostoc, Scytonema)
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)
On otherwise dry surfaces with short periods of water seepage after rain

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model

Harrie Sipman - As Caloplaca oasis

Harrie Sipman – Source - As Caloplaca oasis

Degelius G. 1954. The lichen genus Collema in Europe: Morphology, Taxonomy, Ecology. Symbolae Bot. Upsal. 13, 2: 1-499.