FOUR WESTERN CHEILANTHOID FERNS IN OKLAHOMA

The diversity of ferns in some of the more arid climates of western Oklahoma is surprising. This article examines four Oklahoma cheilanthoid ferns: Astrolepis integerrima, Cheilanthes wootonii, Notholaena standleyi, and Pellaea wrightiana. With the exceptions of A. integerrima and P. wrightiana which occur in Alabama and North Carolina respectively, all four species reach their eastern limits of distribution in Oklahoma. Included in this article are common names, synonyms, brief descriptions, distinguishing characteristics, U.S. and Oklahoma distribution, habitat information, state abundance, and a dichotomous key to selected cheilanthoids. The Oklahoma Natural Heritage Inventory has determined that all but one (N. standleyi) are species of concern in the state.