Acarospora sulphurata (Arnold) Arnold var. sulphurata

Verh. zool.-bot. Ges. Wien, 36: 63, 1886. Basionym: Acarospora heufleriana v. sulphurata Arnold - Verh. zool.-bot. Ges. Wien, 22: 290, 1872.
Distribution: N - TAA, Piem (Isocrono & al. 2003), VA (Piervittori & Isocrono 1999). S - Camp (Aprile & al. 2002), Cal (Puntillo 1996), Si (Grillo & Caniglia 2004).
Description: Thallus crustose, areolate-placodioid, bright yellow to (rarely) greenish yellow in shade-forms, matt, forming up to 4 cm wide rosettes. Lobes 0.5-1 mm wide and long, crenate, plane; central areoles irregular in shape, c. 1 mm wide, contiguous, flat to subconvex, separated by deep fissures. Cortex 35-50 µm thick, opaque, with more or less perpendicular hyphae; algal layer continuous; medulla white, 135-170 µm thick, with crystals dissolving in K. Apothecia lecanorine, up to 10 per areole, at first punctiform and immersed, then slightly expanded, 0.1-0.3 mm across, with a yellowish brown, round to irregular, plane to slightly concave disc and a thin, often indistinct margin. Proper exciple indistinct or to 15 µm wide; epithecium yellowish green to yellowish brown; hymenium colourless, 100-120 µm high; paraphyses 2-2.5 µm thick, the apices hardly swollen. Asci >100-spored, clavate, the apical dome conspicuous, K/I-. Ascospores 1-celled, hyaline, globose to subglobose, 2-4(-5.5) x 2-3(-4) µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-. Chemistry: rhizocarpic acid.
Note: a species of dry-continental areas found on basic siliceous rocks, often on steeply inclined to underhanging surfaces near the ground, in dry grasslands, both in dry Mediterranean areas and in continental Alpine valleys below the subalpine belt.
Growth form: Crustose placodiomorph
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

P.L. Nimis CC BY-SA 4.0
TSB 35423

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (35423)

Domenico Puntillo; Owner: Domenico Puntillo
Italy, Puntillo 12982

Leif Stridvall - Source: (Courtesy: Anita Stridvall)

Leif Stridvall - Source:
Courtesy: Anita Stridvall

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (35423)