Polymeridium inspersum

Polymeridium inspersum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. Found in pantropical regions, it was formally described as a new species in 2013 by Dutch lichenologist André Aptroot. This lichen closely resembles Polymeridium subcinereum but is differentiated by its. The type specimen of P. inspersum was collected by the author in Kuranda, Queensland, along the Jumrum Creek track, growing on a twig.

The thallus of P. inspersum is and pinkish-grey, exhibiting no fluorescence under ultraviolet light (UV−). The ascomata are 0.4–0.6 mm in diameter, with a spherical that is  and solitary. The ostiole is apical, and the is inspersed with oil droplets, featuring filaments that profusely anastomose. Each ascus contains 8 ascospores, which are iodine-negative, 3-septate, and measure 16–20 by 3–5 μm. The are not ornamented, and their walls are not thickened. No chemical substances are detected in P. inspersum.

Polymeridium inspersum has a pantropical distribution, with reported specimens from Brazil and the Philippines. The type specimen and another Australian specimen were previously identified as P. subcinereum by Aptroot. Additional specimens have been examined from Queensland, Australia, and Chapada do Araripe, Ceará, Brazil.