Lecanora orientoafricana Kirika & Lumbsch

Kirika, Paul, Parnmen, Sittiporn & Lumbsch, Thorsten, 2012, Two new species of Lecanora sensu stricto (Lecanoraceae, Ascomycota) from east Africa, MycoKeys 3, pp. 37-47 : 42-43

Lecanora orientoafricana Kirika & Lumbsch sp. nov. Figure 2

Type.

Kenya, Rift Valley Prov., Cherangani Hills, Kerer forest, degraded montane forest, 3240m, on bark, 25.07.2011, P. Kirika 2205 (EA, holotype, F-isotype).

Description.

Thallus crustose, verrucose to verruculose, thin to thick, glossy, whitish to greenish grey; margin indistinct; prothallus not visible; sorediate. Soralia roundish, 0.3-1.0 mm diam., with granulose soredia, light pale greenish white to grayish green. Apothecia sessile, constricted at base, 0.4-1.4 mm diam., lecanorine; disc light red-brown to brown, matt, plane or concave, sparsely grayish pruinose; margin concolourous with thallus, prominent, thick, smooth, verruculose. Amphithecial cortex uniform, gelatinous, inspersed with crystals, hyaline, 20-30 µm thick. Amphithecium with large crystals (= pulicaris–type). Hypothecium red-brown to yellowish brown, 30-40 µm high, parathecium hyaline, lacking crystals, 5-7 µm thick. Hymenium hyaline, 70-85 µm high, clear. Epihymenium red–brown, 10-12 µm thick, with coarse crystals; pigmentation and crystals dissolving in K (= chlarotera–type). Paraphyses sparingly branched, apically slightly swollen, hyaline. Asci clavate, 50-60 × 10-12 µm, 8-spored. Ascospores ellipsoid to broadly ellipsoid, 12.5-15.5 × 6.0-8.5 µm. Pycnidia not seen.

Chemistry.

Thallus and apothecial margin K+ yellow, C-, KC–, containing atranorin and gangaleoidin.

Etymology.

The new species is named after the area East Africa where it has been collected.

Notes.

Lecanora orientoafricana is characterized by the presence of granular soredia, sparsely pruinose, brown apothecia, a pulicaris-type amphithecium, chlarotera-type epihymenium, dark hypothecium, broadly ellipsoid ascospores, and the presence of atranorin and gangaleoidin. Soredia are rare among Lecanora sensu stricto species with a dark hypothecium. Some specimens of Lecanora coronulans are sorediate, but this species is readily distinguished by epruinose apothecial discs, an egranulose epihymenium, and the presence of protoconstipatic acid and zeorin and major constituents in addition to atranorin ( Lumbsch et al. 1996). Similar esorediate species include Lecanora egranulosa and Lecanora phaeocardia . The latter differs from Lecanora orientoafricana in having epruinose apothecial discs, a thinner amphithecial cortex, and alternative chemistry. Lecanora egranulosa is readily distinguished by darker, epruinose apothecial discs, an indistinct, thin amphithecial cortex, small crystals in the epihymenium, shorter ascospores, and the presence of zeorin ( Lumbsch et al. 1996).

Ecology and distribution.

This new species is currently only known from the type locality in the Rift Valley province of Kenya, where it was found growing on bark in a degraded montane forest dominated by Podocarpus falcatus , Rapanea melanophloes and Faurea saligna at an altitude of 3240m. Associated species included Sphaerophorus melanocarpus , Pannaria cf. rubiginosa , and Ramalina spp.