Sticta tainorum is a rare species of foliose lichen in the family Peltigeraceae. Found in Puerto Rico, it was formally described as a new species in 2020 by Joel MercadoâÂÂDÃÂaz and Robert Lücking. The type specimen was collected by the first author in Toro Negro State Forest at an elevation of . It is only known to occur on a few trees in high-elevation forests on the eastern part of the island, near Pico Doña Juana. The specific epithet refers to the indigenous TaÃÂno people.