Rhus toxicodendron var. trilobata M.J. Young, Familiar Lessons Bot. 197. 1873 (“ Trilobate ”), nom. nud. Toxicodendron radicans (L.) Kuntze, Revis. Gen. Pl. 1:153. 1891. Young (1873) divided Rhus toxicodendron L. (= Toxicodendron radicans) into four varieties. Three were noted explicitly and the fourth presumably was the nominate variety. No description accompanies R. toxicodendron var. trilobata. Young (1873) simply states “Found in the northern part of Texas.” There is no indication that Young (1873) is proposing a new combination and change in status based on R. trilobata Nutt., which was described from the Rocky Mountains but also occurs in Texas.

Published as part of Dorr, Laurence J., 2022, New Species And Combinations Published In M. J. Young'S Familiar Lessons In Botany With Flora Of Texas (1873), pp. 29-46 in Journal of the Botanical Research Institute of Texas 16 (1) on page 43, DOI: 10.17348/jbrit.v16.i1.1218, http://zenodo.org/record/16906407