Leptogium terrenum Nyl.

Bull. Soc. Linn. Normandie, 2, 6, 1872.
Synonyms: Amphidium terrenum (Nyl.) Nyl.; Epiphloea terrena (Nyl.) Trevis.; Leptogium crozalsianum Harm.
Distribution: N - Lig (Watson 2014).
Description: Thallus subcrustose to subsquamulose, pale brown to yellowish grey, sometimes thin and inconspicuous, when well-developed formed by 0.4-1.2 mm broad and 0.1-0.2 mm thick, digitate-lobulate areoles radiating all around the apothecia; lower surface paler, attached by stout, pale rhizohyphae composed of 1-2 rows of isodiametric cells. Thallus paraplectenchymatous in section. Apothecia frequent, without a distinct thalline margin, but often containing algal cells at the base of the proper margin, round, sessile, 0.5-1 mm across, with a reddish brown to brown-black, flat, smooth disc and a thin, smooth, persistent proper margin. Proper exciple distinct, colourless, composed of small cells, the basal parts often with clumps of photobionts; epithecium reddish brown; hymenium colourless, 100-125 µm high, K/I+ blue; paraphyses simple, straight, 1.5-2 μm thick, the apical cells slightly swollen; hypothecium colourless to pale brown. Asci 8-spored, narrowly clavate, with a distinct, amyloid, tube-like apical structure. Ascospores submuriform, with 4-7 transverse septa and a few longitudinal septa, hyaline, narrowly ellipsoid, (15-)18-26(-38) x (5-)9-14 µm. Photobiont cyanobacterial (Nostoc), in more or less rounded clumps. Spot tests: all negative. Chemistry: without lichen substances.
Note: on bare siliceous soil in Mediterranean grasslands and garrigues; probably much overlooked in Italy, but certainly not common, being known from a single station in Liguria.
Growth form: Crustose
Substrata: soil, terricolous mosses, and plant debris
Photobiont: cyanobacteria, filamentous (e.g. Nostoc, Scytonema)
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

P.L. Nimis CC BY-SA 4.0
GZU Ref.Herb. Poelt (2-93)

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: GZU Ref.Herb. Poelt (2-93)