Caloplaca fluviatilis Vondrák & I.V. Frolov, 2019

Vondrák, Jan, Frolov, Ivan, Davydov, Evgeny A., Yakovchenko, Lidia, Malíček, Jiří, Svoboda, Stanislav & Kubásek, Jiří, 2019, The lichen family Teloschistaceae in the Altai-Sayan region (Central Asia), Phytotaxa 396 (1), pp. 448-450 : 448-450

Caloplaca fluviatilis Vondrák & I.V. Frolov , species nova

MycoBank: MB826775

Figs: 5B, 6.

Etymology: The name refers to the ecology of the species; it occurs in rivers. Type:— RUSSIA. Republic of Tyva: Ak-Dovurak, Alash, 2 km SE of village Ak-Sug, siliceous rocks in forest-steppe, in valley of river

Mungash-Ak, alt. 1120 m, 51.4003N, 90.4448E, on siliceous stone in river, occasionally inundated, 8 July 2013, Ivan Frolov & Jan

Vondrák 18229 (holotype PRA). Type sequence: MG954128 ( ITS) .

Diagnosis: Thallus thin (<100 μm thick), rimose areolate in center, film-like and effuse at margins, without vegetative diaspores. Thallus and the lecanorine apothecial margin usually pale grey, with low content of Sedifolia-grey pigment. Apothecial disc pale orange, or pale yellow when in damp and shady conditions. Its occurrence on occassionally inundated siliceous boulders is distinctive. Caloplaca cerina and C. stillicidiorum are similar but epiphytic. Caloplaca chlorina , occurring in similar substrates and habitats, has vegetative diaspores.

Ecology and Geography : On occasionally inundated siliceous boulders in river, in rather damp and shaded sites. Only known from two sites on southern slopes of Western Sayan in the Republic of Tyva ( Russia). It is abundant in the two localities and presumably is common in rivers Ak-Sug and Kara-Sug at altitudes 1100–1500 m, in a forest-steppe zone .

Phylogeny: In the ITS tree, it belongs to Caloplaca sensu stricto forming a clade within the large group including Caloplaca stillicidiorum lineages ( Fig. 6 ).

Taxonomy. Ecologically very distinct from all close lineages of C. stillicidiorum which are confined to organic substrates. Morphologically distinct from all known epilithic species by absence of vegetative diaspores, pale colour of thallus and apothecia, and film-like effuse thallus.

Paratypes: Russia, Republic of Tuva, West Sayan Mts, Ak-Dovurak , Ak-Sug , 2 km N of settlement Enge-Beldir , boulders in river Kara-Sug , alt. 1490 m, 51.618896N, 90.076410E, 8 July 2013, Ivan Frolov 1313 (Frolov’s personal herbarium), Jan Vondrák 11104, 18213 ( PRA); The type locality, 8 July 2013, Ivan Frolov 630, 631, 634 (Frolov’s personal herbarium) .

Caloplaca isidiigera : 3 localities at altitudes 1570–2180 m, in humid alpine habitats. Substrate: base-rich siliceous rocks (mica-schist, sandstone). More information in Vondrák et al. (2016a).

Caloplaca monacensis : Once recorded at altitude 500 m in humid non-alpine habitat (specimen Vondrák 18032). Substrate: bark of Populus sp.

Caloplaca stillicidiorum s.lat.: 30 localities at altitudes 390–2950 m, in all ecological classes, but more frequent in dry habitats and alpine habitats. Known from various organic substrates: wood, bryophytes, twigs of shrubs in steppe and above timber line; perhaps only exceptionally on trees. Šoun et al. (2011) reported several groups within C. stillicidiorum that may be separate species. More than one group may be present in the Altai-Sayan region.

Caloplaca subalpina : Recorded once at altitude 1575 m in humid alpine habitat. Substrate: mica-schist, vertical rock faces or below overhangs. More information in Vondrák et al. (2016a).

Caloplaca turkuensis : Recorded once at altitude 1120 m in a forest-steppe zone (specimen Vondrák 18405). Substrate: wood of Larix . Often forming grey blastidiate crusts without apothecia; perhaps more frequent in the region.

Figures

FIGURE 6. Bayesian phylogenetic reconstruction of a part of the genus Caloplaca (sensu stricto) using the ITS DNA locus. The epilithic Caloplaca fluviatilis is unresolved in polytomy with epiphytic lineages of C. cerina and C. stillicidiorum.