Ocelullaria vallensis Soto-Medina & Lücking, sp. nov.

(Fig. 2)

A new Ocelullaria similar to O. buckii Lücking, but differing in the larger ascospores and fewer septae.

HOLOTYPE. — Colombia. Valle del Cauca, Municipio Andalucía, Hacienda el Verdún, 4°06’30”N, 76°07’09”W, 1056 m, tropical dry forest, 8-13.XII.2020, Soto Medina 87 VER (holo-, TULV).

ETYMOLOGY. — The epithet refers to the Valle del Cauca, in short “Valle”.

ECOLOGY. — This species grows on bark of Simira Aubl. in tropical dry forest.

CHEMISTRY. — Thallus UV–, K–, C–; medulla C–, K–, KC–.

MYCOBANK. — MB 849070.

DESCRIPTION

Thallus corticolous, crustose, up to 7 cm diam., continuous; surface shallowly verrucose-rugose, green-gray to grey; prothallus absent. Photobiont of a species of Trentepohlia . Ascomata rounded to slightly irregular in outline, immersed-erumpent, with almost complete thalline margin, 0.4-0.6 mm diam., 0.1 mm high; disc covered by 0.07-0.15 mm wide pore, filled by black-tipped columella; proper margin distinct, visible as brown-black rim around the pore; thalline margin entire, smooth to shallowly verrucose, grey. Excipulum entire, in lower portion brown, apically carbonized, about 30 µm wide; columella present, finger-like, up to 90 µm broad and 120 µm high, completely carbonized; hypothecium 5-10 µm high, hyaline; hymenium up to 120 µm high, hyaline, not inspersed. Paraphyses unbranched, apically smooth; periphysoids absent; asci cylindrical to clavate, about 120 × 17 µm. Ascospores 8 per ascus, more or less uniseriate, ellipsoid, 3-septate, about 42-45 ×14-15 µm, I+ violet-blue.

NOTES

With its columellate apothecia, the small, hyaline, transversely-septate ascospores, and the lack of secondary compounds, Ocelullaria vallense Soto-Medina & Lücking, sp. nov. is to be placed into the O. papillata (Leight.) Zahlbr. complex sensu Lücking (2015). In this complex, there are four species with apically carbonized excipulum and carbonized columella. Ocellularia marmorata L.I.Ferraro, Lücking, Aptroot & M.Cáceres from Argentina differs in the minutely grainy thallus with columnar crystals and the 5-7-septate ascospores, whereas in the paleotropical O. krathingensis Homchant. & Coppins the ascospores are 7-11-septate. The pantropical O. viridipallens Müll. Arg. differs in the more greenish, finely verrucose thallus and the apothecia lacking a blackish proper margin and with an apically pruinose columella. Most similar is O. buckii Lücking from Brazil (Lücking 2015), agreeing well in thallus and apothecial morphology with the new species but has much smaller ascospores (20-25× 7-8µm).