Mentha piperita seeds

Perennial herbs. The stem is upright, with several nodes in the lower part having slender fibrous roots and horizontally hooked rhizome, sharp quadrilateral, with four grooves, the upper part is puberulent, and the lower part is puberulent only along the edges, and is multi-branched. The leaves are oblong-lanceolate; in the seedling stage, the base of the stem is purple and the upper part is green; in the middle and late stages, the base of the stem is lavender and the middle and upper part are green. The veins of the leaves are lavender or bluish white, with sunken paths. The leaves are round or oval in the seedling stage, and oval in the middle and later stages. The leaves are green in the seedling stage, and dark green in the middle and late stages. The corolla is white and slightly blue, with both male and female stamens. The flowering period is from July to September.