Iris latistyla Y. T. Zhao f. albiflora J. Luo, a new form of Iris (Iridaceae) in Xizang of China is described. It differs from the typical form, I. latistyla Y. T. Zhao, by having white petals, which is quite stable. The new form randomly occurs in populations of the typical form. For its potential medicinal research value, a short discussion is given.