Vascular Flora of Alabaster Caverns State Park, Cimarron Gypsum Hills, Woodward County,Oklahoma

Alabaster Caverns State Park is located in the Cimarron Gypsum Hills of northwestern Oklahoma, a semi-arid region of the state. The majority of the park is dominated by mixed-grass prairie and gypsum outcrops, with some riparian habitat and wooded north-facing slopes. A vascular plant inventory conducted from 2004 through 2007 yielded 274 species in 199 genera and 66 families. The largest families were the Poaceae (52 species), Asteraceae (47), and Fabaceae (23). There were 100 annuals, 6 biennials, and 163 perennials, as well as 5 species that have more than one life history form. Forty-two species (15.3%) were not native to North America. Three taxa currently being tracked by the Oklahoma Natural Heritage Inventory (2012) were present: Echinocereus reichenbachii (S3G5), Haploesthes greggii (S1G4?), and Marsilea vestita (S1G5). Compared to floristic inventories of sites in the Cimarron Gypsum Hills that are less impacted by public visitation, but more intensively grazed, Alabaster Caverns State Park has a higher number of species as well as a higher proportion of introduced species.