Nelsonia canescens (Lam.) Spreng. (ACANTHACEAE)—Sarasota County, Sarasota, Rothenbach Park, 1.1 km E of Bee Ridge Road Extension (Iona Road), 4.1 km N of FL 72, 27u179210N, 82u239240W, 13 February 2011, A. R. Franck 2556 (USF), 27 February 2011, A. R. Franck 2557 (CAS, USF), 7 April 2011, A. R. Franck 2601 (CAS).
Significance. This represents the first known occurrence of this genus and species in the United States, and adds to the growing list of tropical species that have become naturalized in Florida. The plants were found trailside in a ca. 35 m2 mown lawn of Paspalum conjugatum P.J. Bergius under the shade of a mesic Quercus virginiana Mill. hammock; associates include Cyperus croceus Vahl, Kyllinga sp., Ruellia blechum L., and Salvia misella Kunth. Between 10 and 20 distinct colonies occupy ca. 20% of the lawn area. The largest colony occupies ca. 5 m2.