Hockett, E. A. and R. F. Eslick. 1969. Genetic male sterile genes useful in hybrid seed production. Wiebe, G. A. and J. D. Hayes. The role of genetics in the use of agricultural chemicals. Leaves of young seedling bend with wrinkles at the margins.
Culms bend at nodes.
Upper part of the top internode grow spiralized. Awns often curved. Allelism test showed that this gene is not allelic to cu2 for curly 2 in chromosome 3. Based on this information the symbol cu4 was given to this mutant. Furst, E. C. 1983.