A Floristic Study of the Vascular Plants of the Gypsum Hills and Redbed Plains Area of Southwestern Oklahoma

The vascular floras of gypsum and redbed soils in southwestern Oklahoma were collected and studied during the growing season (April-October) of 1975. A total of 359 taxa and 230 genera and 63 families were included in the study. Thirteen taxa are considered to be gypsophiles and indicators of gypsum soils in Oklahoma. Nine taxa are considered calicoles occurring only on gypsum and limestone derived soils. Two introduced species, Bromus catharticus Vahl (syn. = Bromus willdenowii) and Caesalpinia gilliesii, are believed to be new additions to Oklahoma’s flora.