Verbatim text: Johnston, M. C. 1963. The species of Ziziphus indigenous to United States and Mexico. Amer. J. Bot. 50: 1020–1027.
Author: Johnston, M.C.
Year: 1963
Title: The species of Ziziphus indigenous to United States and Mexico
Journal: Amer. J. Bot
Volume: 50
Pages: 1020–1027