About Umbilicaria polyphylla (L.) Baumg.
Umbilicaria polyphylla, commonly called petaled rock tripe, is a widely distributed species of saxicolous lichen belonging to the family Umbilicariaceae. Carl Linnaeus first described this species in his 1753 work Species Plantarum, under the name Lichen polyphyllus. In 1790, German botanist Johann Christian Gottlob Baumgarten moved this species to the genus Umbilicaria. This lichen has a dark brown to black thallus, which reaches 2–6 cm (0.8–2.4 in) in diameter. Its upper surface is smooth, while its lower surface is sooty black. It grows on exposed rocks, most commonly in arctic-alpine habitats. In Iceland, this species holds the conservation status of vulnerable (VU).
