Verrucaria ahtii Pykälä, Launis & Myllys
Lichenologist, 49: 108, 2017
Synonyms:
Distribution:
Description: Thallus crustose, thinly episubstratic and fleck-like, subgelatinous when wet, continuous or rimose, pale to medium brown, rarely grey, c. 0.02-0-15(-0.25) mm thick, the surface uneven, consisting of small, 0.03-0.08(-0.13) mm wide units, often delimited by a rather inconspicuous, fimbriate prothallus. Cortex c. 10-24 μm thick, the cortical cells brown. Perithecia black, 0.15-0.32 mm across, 60-180(-220)/cm2,(25-)50-75%-immersed in thallus (not leaving pits), often with a c. 11-24 μm thick thalline cover. Ostiole inconspicuous, flat to depressed or often appearing as a c. 20-30(-50) μm wide, dark, projecting papilla; involucrellum usually extending to base-level, rarely only exceeding half of the exciple, (20-)30-50 μm thick, appressed to exciple or slightly diverging; exciple 0.16-0.25(-0.32) mm across, the wall usually dark brown, c. 13-18 μm thick. hamathecium of sparingly branched periphysoids measuring c. (20-)25-30(-40) x (1.5-)2-2-5(-3) μm, interascal filaments absent; hymenial gel hemiamyloid, I+ red (I+ blue at very low concentrations of I), K/I+ blue. Asci 8-spored, clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of an endotunica to form a delicate rostrum, Verrucaria-type. Ascospores 1-celled, hyaline, ellipsoid, (17-)20-25(-28) x (9-)10-12(-14) μm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances. Note: a calcicolous species described from Northern Europe, recently also reported from Switzerland. To be looked for in Italy.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Predictive model
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Predictive model
