The recessive flower color in Mendel’s pea plants was white.
Mendel compared pea plants with violet or purple flowers against plants with white flowers. When he crossed true-breeding plants from these two lines, every plant in the first-generation offspring produced violet-colored flowers. Because the white trait disappeared visibly in that generation, he classified it as recessive.
The white flowers were not eliminated genetically. In the next generation, produced by allowing the hybrids to reproduce, white-flowered plants reappeared in roughly one-quarter of the offspring. This pattern helped Mendel distinguish between an inherited factor and the visible trait itself.
Modern genetics explains the result through alleles: a plant needs two copies of the recessive version to show white flowers, while one dominant allele is enough to produce the colored phenotype. Older descriptions may say “violet” rather than “purple,” but white is the canonical recessive answer. Flower color was one of seven contrasting characteristics Mendel studied in Pisum sativum.