Blastenia A.Massal.
Thallus crustose, uniform, continuous, powdery, granular or cracked, attached to substrate by medullary hyphae or those of prothallus, homoiomerous or heteromerous, ecorticate. Photobiont green, Trebouxia. Apothecia rounded, lecideine, without a thalline margin, immersed or sessile, pruinose or not, K+ purple (anthraquinones). Hypothecium pale yellowish to colourless. Paraphyses distinct, septate, capitate, slightly swollen and often granular pigmented at apices, septate. Ascospores colourless, ellipsoid, ovoid or elongate, with rounded or slightly pointed ends, polaribilocular, 4-16 per ascus. Pycnidia immersed, spherical. Conidia short, cylindrical, straight, rarely curved.
Blastenia is a cosmopolitan genus of c. 76 species included in the family Teloschistaceae. It is separated from taxa in Caloplaca by the lecideine apothecium. One species is discussed here but the genus is very poorly known and collected in New Zealand.
