Kenya, Eastern Prov., Mount Kenya National Park, Chogoria Track, close to Chogoria Gate, open Juniperus-Podocarpus woodland, 0°09'S, 37°26'E, 2960m alt., 27.01.2010, on Juniperus, P. Kirika 1179, G. Mugambi & H.T. Lumbsch (holotype EA, isotype F).

Thallus crustose, verrucose to verruculose, thin to thick, glossy, whitish to greenish; margin indistinct; prothallus not visible; sorediate. Soralia roundish, concave, 0.5–1.2 mm diam., remaining distinct or coalescing, with granular soredia, yellowish green to yellowish gray. Apothecia sessile, strictly constricted at base, 0.6–2.0 mm diam., lecanorine; disc red-brown, shiny, plane, epruinose; margin concolourous with thallus, prominent, thick, smooth, entire to verruculose, flexuose. Amphithecial cortex uniform, gelatinous, inspersed with crystals, hyaline, 25–45 µm thick, with hyphae growing out basally. Amphithecium with small and large crystals (=melacarpella-type). Hypothecium hyaline, 25–30 µm high, parathecium hyaline, with yellowish crystals, 5–7 µm thick. Hymenium hyaline, 55–70 µm high, clear. Epihymenium red–brown, 10–12 µm thick, with numerous, small crystals; pigmentation and crystals dissolving in K (=pulicaris–type). Paraphyses sparingly branched, apically slightly swollen, hyaline. Asci clavate, 50–60 × 10–14 µm, 8–spored. Ascospores ellipsoid to narrowly ellipsoid, 12–17 × 4.5–6.5 µm. Pycnidia not seen.

Thallus and apothecial margin K+ yellow, C-, KC–, containing atranorin (minor), and usnic acid (major).

The new species is named after the country Kenya where the new species has been found.

Lecanora kenyana is characterized by relatively large, red-brown apothecia with a constricted base, a melacarpella-type amphithecium, pulicaris-type epihymenium, the presence of usnic acid as major constituent, and the presence of soralia. There are only few sorediate Lecanora sensu stricto species with usnic acid, including Lecanora brodoana, Lecanora elatinoides, Lecanora floridula, Lecanora jamesii, Lecanora mobergiana, and Lecanora transvaalensis (Brodo and Elix 1993; Lumbsch and Elix 1998; Lumbsch et al. 1995; Lumbsch and Nash 1995). The saxicolous Lecanora brodoana and Lecanora mobergiana differ in having an egranulose epihymenium among other characters, whereas Lecanora elatinoides (containing pannarin) and Lecanora jamesii (containing 2-O-methylsulphurellin) are readily distinguished by their alternative chemistry and smaller ascospores. Similar species include Lecanora floridula described from Florida (USA) and Lecanora transvaalensis from South Africa. The former species can be distinguished by having smaller apothecia (up to 1 mm), thinner and poorly developed amphithecial cortex, a chlarotera-type epihymenium, smaller ascospores, and the presence of unidentified triterpenes (Lumbsch et al. 1995). Lecanora transvaalensis differs from Lecanora kenyana in having smaller apothecia (up to 0.9 mm), a thinner and poorly developed amphithecial cortex, and smaller, broadly ellipsoid ascospores (9.5–11.5 × 7.0–8.5 µm). Further, it contains unidentified terpenoids (Lumbsch et al. 1995).

At present this species is known from bark of juniper trees in open habitats at altitudes above 2800m in forests dominated by Hagenia and Podocarpus. Associated lichens included Heterodermia leucomelos, Lecanora caesiorubella, Leptogium laceroides, Lobaria pulmonaria, Pannaria fulvescens, Physcia albata, Pseudocyphellaria aurata, Physcia crocata, Varicellaria velata, and several Usnea spp.

Kenya: Eastern Prov., Mt. Kenya National Park, Sirimon route, ca. 3km for KWS gate towards Old Moses Camp, 00°00'N, 37°15'E, mature montane forest with Podocarpus, Olea, Hagenia and Arundinaria alpina, 2870m, on bark, 7.10.2010, P. Kirika 2051, G. Mugambi, G. Gatere and M. Mutembei (EA).

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

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.

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

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

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).

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.