Additional notes on Arthraxon. 20 August 2011
Jason Singhurst (Texas Parks and Wildlife Dept.) notes that Arthraxon hispidus indeed does occur in other east Texas localities. He and Walter Holmes have made collections from Marion, Smith, and Bowie counties in the northeastern corner of the state, all relatively near the original locality reported by Brown and Schultz in Cass County.
Larry Dorr notes that Arthraxon hispidus has been recorded as naturalized in the Caribbean (Jamaica, Guadeloupe), Central America (Guatemala), and Mexico (Chiapas) and cites a publication that recorded its occurrence in South America –– in Venezuela, in the adjacent western states of Portuguesa and Trujillo.
Dorr, L.J. and S.M. Niño. 2001. Arthraxon (Poaceae: Andropogoneae) new to South America. Sida 19: 1191–1193.
Many thanks to Jason and Larry for their comments.