Taxonomic and Ethnobotanical Investigations of the Vascular Flora of Oklahoma

Abstract

Between 2006 and the present, three taxonomic investigations of the flora of Oklahoma were conducted. Results of these studies are summarized in the following paragraphs: In a two-year floristic inventory of the Eagle Pass, Sally Bull Hollow, and Workman Mountain tracts of the Ozark Plateau National Wildlife Refuge and the adjoining Ozark Plateau Wildlife Management Area, 442 species of vascular plants in 285 genera and 88 families were encountered. Ninety-two percent of the species were native and the largest families were Asteraceae, Fabaceae and Poaceae, together constituting 33% of the total taxa present in the three tracts. Eighty-five species collected were new records for Adair County. Nineteen species designated as rare by the Oklahoma Natural Heritage Inventory (OHNI) were encountered. Preparation of a taxonomic treatment of the genus Eragrostis (Poaceae) for theFlora of Oklahoma revealed that 14 native and 6 introduced species of the genus are present in the state. Eighty vegetative, inflorescence, and spikelet features of each species were measured or scored. The range of variation for each character was determined and recorded. Descriptions of each species were written. Nomenclatural, taxonomic, and ecological notes were added as appropriate to complement the morphological descriptions. A dichotomous key to the 20 species was prepared. An examination of the toxicity of six populations of Tephrosia virginiana (Fabaceae) in Oklahoma revealed all root extracts to exhibit acute toxicity in a standard laboratory bioassay using larval fathead minnows (Pimephales promelas). Isolation and identification of the compound or compounds responsible were not undertaken. The variability among the replicates within sites produced few statistically significant differences among the six populations. Correlations between toxicity and edaphic factors were inconclusive.