Herre's Ragged Lichen

Platismatia herrei is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. It was first formally described as a species of Cetraria in 1968 by lichenologist Henry Imshaug. William and Chicita Culberson transferred it to the genus Platismatia in 1968. The lichen is found in western North America, ranging from southern Alaska to central California. It is distinguished from other members of its genus by the isidia that fringe the edges of its linear lobes; the Culbersons described it as "one of the most beautiful and intricately formed species in the genus".

Platismatia herrei reproduces primarily asexually through the production of isidia. Its thallus is whitish or pale, often splotched with black, with flat to curled inwards lobes that are narrow and linear. The upper surface is smooth to very minutely pitted or wrinkled. The lower surface is white or pale with discrete and delimited black zones. It has few black rhizines, present only at places of attachment.