Zephyranthes grandiflora frequently displays flowers with extra parts and has been widely distributed as an ornamental. Flowers with extra parts have been seen in Z. atamasca, Z. candida, Z. rosea, and Z. treatiae. Zephyranthes grandiflora also has been found to have a variable number of chromosomes in cells from single plants (R. O. Flagg 1961).
As a rule, the flowers of Zephyranthes species having high chromosome numbers, 2n = 48 or more, are built for self-fertilization, with the stigma borne very near (within 2 mm), among, or beneath the anthers (R. O. Flagg and W. S. Flory 1962). However, Zephyranthes grandiflora is an exception and often exhibits poor fertility.