A new gene for flower color pattern, designated white banner (WB), appeared in material derived from the cross `Harvester' snap bean (Phaseolus vulgaris L.) × Plant Introduction (PI) accession 273666 of scarlet runner bean (P. coccineus L.). The WB character has a white banner petal and pale violet wings (veronica-violet 639/2). The inheritance of the mutant was studied in crosses involving dry bean breeding line 5-593, which has bishops-violet (wild-type) flowers, and genetic stocks v BC2 5-593 (white flowers) and blu BC2 5-593 (blue flowers). Segregation in F2 and F3 progenies from the cross v BC2 5-593 × WB supported the hypothesis that WB is controlled by a single recessive gene that is nonallelic with the V locus. An allelism test with blu BC2 5-593 gave evidence that WB is not allelic with the blu locus. The gene symbol wb is proposed for the gene producing WB.