Found in the forests of Minas Gerais, Brazil, this species is distinguished by its unique spindle-shaped ascospores, which are more than four times as long than they are wide.

Pyrenula fusoluminata was described in 2002 by the Dutch lichenologist André Aptroot from specimens he collected in the Serra do Caraça in Minas Gerais, Brazil.

[2] The thallus of Pyrenula fusoluminata is crustose, reaching up to 10 cm in diameter, with a yellowish brown colour and a somewhat glossy finish without any pseudocyphellae or visible hypothallus.

[2] Perithecia (fruiting bodies) are hemispherical and black, measuring 0.7–1.2 mm in diameter, with the basal half often covered by the thallus.

Asci (spore-bearing cells) are cylindrical to clavate (club-shaped), measuring approximately 95–110 by 8–11 μm, and typically contain four, occasionally five, ascospores.