Bacidia primigenia Vain. (1928: 95)

Gerasimova, Julia V. & Ekman, Stefan, 2017, Taxonomy and nomenclature of seven names in Bacidia (Ramalinaceae, Lecanorales) described from Russia, Phytotaxa 316 (3), pp. 292-296 : 294-295

Bacidia primigenia Vain. (1928: 95)

Type:— RUSSIA. Khanty-Mansiysk Autonomous Okrug: ”Sibiria occ.: Amensk”, [23–24 July acc. to Alava (1988)] 1880, E. Vainio s. n. (holotype: TUR-V 20803!).

The type material of Bacidia primigenia was collected on sandy soil covering pine roots along Konda River, a tributary to the Irtysh River in western Siberia. The specimen is, unfortunately, not well preserved, consisting of three smaller envelopes of loamy sand, only some coherent and with observable lichen thalli. Vainio (1928) described it as (in translation) ‘closely related to Arthrorhaphis flavovirescens ’ (a synonym of A. citrinella ), having black, sessile, urceolate apothecia that are hardly constricted at the base and measure 0.15–0.2(–0.4) mm across. Spores were described as narrowly fusiform, 17–28 × (2.5–)3–4 μm and with 3–5 septa. We have confirmed that Vainio’s observations were indeed correct. The apothecia are attached to a thin, pale (pale bluish according to Vainio), areolate thallus that may very well belong to a member of Baeomyces .

Bacidia primigenia belongs, as predicted by Vainio (1928), to the genus Arthrorhaphis . Although spores are somewhat on the short side and have fewer septa than normally expected, we cannot exclude the possibility that B. primigenia is conspecific with A. grisea Th. Fr.