Porina albotomentosa is a rare species of foliicolous (leaf-dwelling) lichen in the genus Porina, described as a new species in 2022. It is identified by its hemispherical (fruiting bodies) adorned with a white, and its 3-septate, spindle-shaped . This species was first discovered on living leaves within a Cerrado forest remnant in Mato Grosso do Sul, Brazil.
Porina albotomentosa was formally described as a new species in 2022 by the Dutch lichenologist André Aptroot. The specific epithet albotomentosa refers to the distinctive white (short fungal hyphae with a texture similar to velvet) covering its ascomata, an unusual feature that sets it apart from other species within the genus Porina.
The thallus of Porina albotomentosa appears somewhat polished and ochraceous grey, forming patches up to 1 cm in diameter. It is quite thin, lacks a prothallus, and has algae as its . The perithecia are notable for their hemispherical shape, constricted base, and nitidous, red-brown colour, measuring 0.2–0.3 mm in diameter and approximately 0.2 mm in height. These perithecia are, not covered by the thallus, and are densely covered by a white tomentum. The species produces 8 ascospores per ascus, which are hyaline (translucent), 3-septate, and spindle-shaped, measuring 12–14 by 4–5 μm.
Chemical tests on the thallus of Porina albotomentosa showed no reaction to UV light, nor to common chemical spot tests.
This lichen is solely known to occur in its type locality in Campo Grande, Mato Grosso do Sul, Brazil. It inhabits the living leaves of plants in Cerrado forests, a type of savanna-like ecosystem.