Diadelphian

Di`a`del´phi`an


a.1.(Bot.) Of or pertaining to the class Diadelphia; having the stamens united into two bodies by their filaments (said of a plant or flower); grouped into two bundles or sets by coalescence of the filaments (said of stamens).
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.