This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Perennial. Propagates by seeds and by stolons.
Time of bloom: June to September.
Seed-time: August to November.
Range: Nova Scotia to Ontario and Minnesota, southward to Florida and Kansas.
Habitat: Moist ground; fields and waste places.
Like the preceding species this mint is cultivated for the distillation of its oil, which has a milder flavor and action than that of Peppermint. Stems ten to twenty inches high, nearly smooth, erect, square, branching. Leaves lance-shaped, unequally toothed, the surface somewhat puckered and wrinkled, sessile or with very short petioles. Flowers pale purple, in terminal, narrow, pointed, usually interrupted spikes, the subtending bracts long-pointed and conspicuous; calyx-teeth equal, smooth or only slightly hairy and nearly as long as the tube of the corolla which is smooth with upper lip entire or sometimes slightly notched, the lower lip with three rounded lobes; stamens all four of the same length, erect, included. (Fig. 253.) Means of control the same as for Peppermint.
Fig. 253. - Spearmint (Mentha spicata). X 1/4.
 
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