Dermatocarpon (Verrucariaceae) in the Ozark Highlands, North America

Dermatocarpon, a saxicolous lichen, is common throughout the Ozarks Highlands of North America where exposed rock is abundant. Dermatocarpon is an understudied genus. Species delimitation is difficult because of a paucity of morphological characters and a large degree of variation within this genus. The taxonomy of Dermatocarpon in North America was recently thrown into flux because of a molecular study which limited the use of a once widely applied name, D. miniatum. The Melzer's reagent test, currently used for identifying members of the miniatum-complex in North America, is not useful for identifying Ozark specimens. A revision of Dermatocarpon for the Ozark Highlands of North America is presented based on morphological, molecular and ecological studies. The results of these studies indicate that eight taxa are present in the Ozarks. Four taxa are described new to science: D. arenosaxi, D. dolomiticum, D. luridum var. xerophilum and D. multifolium.