Pyrenula cornutispora is a species of corticolous (bark-dwelling) crustose lichen in the family Pyrenulaceae. The species forms a thin smooth yellowish-brown crust on tree bark and produces tiny hemispherical fruiting bodies 0.4âÂÂ0.7 mm across that are largely covered by the thallus except for tiny black pores at the top. It is characterized by distinctive horn-shaped spores with tapered, pointed ends that often curve slightly, and is known only from Amazonas state in Brazil.
Pyrenula cornutispora was described as a new species by André Aptroot and Marcela Cáceres in 2013. The holotype was collected at Fazenda São Francisco (Amazonas, Brazil) off federal highway BR-319, about north of Porto Velho, on tree bark. The epithet refers to the pointed-ended ascospores noted in the .
A thin, smooth yellowâÂÂbrown crust distinguishes this species. The thallus spreads widely without forming a border and shows no pseudocyphellae. Its sporeâÂÂbearing structures protrude as hemispherical domes that are largely covered by the thallus except for a tiny black pore at the top. These domes occur singly and measure roughly 0.4âÂÂ0.7 mm across. The contains minute colorless oil globules. Each ascus holds eight ascospores arranged in two uneven rows. The spores have three crossâÂÂwalls and measure 25âÂÂ29 üm long and 8âÂÂ10 üm wide (extremes of 2 ümm and 32 üm have been noted). Their central chambers are broader than long and the end chambers longer than broad; the spore ends taper to sharp or attenuated points and often curve slightly, giving them a hornâÂÂlike shape. There is no thickened inner wall at the spore tips. Neither Asexual structures nor secondary metabolites have not been observed.
Pyrenula cornutispora is only known to occur in Amazonas state, Brazil.