Bacidia freshfieldii (Vain.) Zahlbr. (1926a: 112)

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 : 293

Bacidia freshfieldii (Vain.) Zahlbr. (1926a: 112)

Lecidea freshfieldii Vain. (1899: 318) . Type:— RUSSIA. Caucasus: “Ardonthal, kieselh. Gest.”, 1885, H. Lojka, Iter Caucasicum 122 (holotype or possibly syntype: TUR-V 21241!).

Bacidia freshfieldii was described from Northern Caucasus, where it was collected on siliceous rock. This species appears to be closely related to Catillaria scotinodes (Nyl.) Coppins and C. aphana (Nyl) Coppins. Like in C. scotinodes , the thallus is rimose, well developed and spreading over the substrate, although thicker and with a warted to almost tuberculate surface. Similarly to C. aphana , apothecia are dominated by a brown (K+ purplish) pigment and by smaller ascospores than C. scotinodes , 9–11 × 3.5–4 μm (according to our own measurements) or 8–12(–16) × 3.0–4.0 μm according to Vainio (1899). Unlike both species, B. freshfieldii has a thick, brownish thallus, relatively large apothecia (up to 0.7 mm diam., many c. 0.5 mm), and a well-developed, thick and persistent proper exciple. Vainio (1899) described ascospores as mainly 1-septate, occasionally 3-septate. We observed only 1-septate ascospores, however. Vainio’s report of 3-septate ascospores is likely to be the reason why Zahlbruckner transferred the species to Bacidia and not to Catillaria .

Although B. freshfieldii is clearly not a member of Bacidia s. str., a reclassification must await the clarification of generic boundaries in the Ramalinaceae .