Nomenclatural notes: Name previously used incorrectly in horticulture and literature to refer to sinkhole dwelling cycad now known as Z. decumbens Calonje, Meerman, M.P.Griff. & Hoese. Determined to be a prior valid name for Z. polymorpha D.W.Stev., A.Moretti & Vázq.Torres by Calonje & Meerman: J. Bot. Res. Inst. Texas 3(1): 43-49. 2009.