Vert. wilt resistant. Fully fertile in summer-grown greenhouse plants, winter-grown usually sterile M. J. Murray notes - M. crispa L. or M. spicata l. var. crispa Schr. 2n = 4x = 48. Verticillium wilt resistant. Fully fertile in summer-grown greenhouse plants. Winter greenhouse plants usually have environmentally-induced sterility. Murray (1968) showed that carvone-odored M. crispa had genotype Cc Aa and segrated 12 spearmint: 3 menthone:1 piperitone in S1 progeny.