Remarks: Cosmarium hornavanense is a variable species and it is not always possible to associate a specific specimen with one of the many varieties and formae that are described in the literature. Specimen 2012008-001 has similarity with var. mesolaeium (Nordstedt) Růžička, specimen 2007002-027 with var. dubovianum (Lütkemüller) Růžička and specimen 2014052-012 with var. janoviense (Gutwiński) Růžička.