Species: Umbilicaria rigida

Thallus foliose, mono- or polyphyllus, rigid and leathery, folded, the margins usually incised or perforate, the umbo becoming chinky areolate or dissected and with a frosty bloom; upper side dull, buff to dark brown or black-brown, chinky-areolate; underside smooth to dimpled and with the lower cortex in a pattern of small areolae, or papillose-areolate to verrucose, dark brown or in brown and black patches, usually marginally darker. Apothecia common, stipitate, the disk flat, the margins slightly shiny (Thomson 1984).