Annual, biennial, perennial herbs or scandent subshrubs to 2 m high. Leaves simple, petiolate, the margins entire to dentate. Flowers terminal in interrupted bracteate spikes, rarely axillary. Calyx campanulate, 5-10 nervate, the lobes subequal and usually shorter than the tube. Corollas mostly blue to purple, sometimes red or pinkish, rarely white, decidedly 2-lipped, the upper of 2 united lobes, the lower lip of 3 spreading lobes. Stamens 4, didymous, the upper pair somewhat longer than the lower. Ovary deeply 4-lobed. Nutlets ovoid to oblong, glabrous or rarely pubescent. Base chromosome numbers, x = 32, 33, 34, 41 (in North America).
The generic name derives from the Greek word stachys , meaning spike-like, such as occurs in the flowering stalks of wheat, with which it was compared by Linnaeus when he described the genus.
Epling, C. 1934. Preliminary revision of American Stachys . Beth. Repert. Spec. Nov. Regni Veg. 80: 1-72.
Mulligan, G. A. & D. B. Munro. 1989. Taxonomy of species of North American Stachys (Labiatae) found north of Mexico. Rev. Ecol. Syst. 116: 35-51.
Nelson, J. B. 1981. Stachys (Labiatae) in southeastern United States. Sida 9: 104-123.
Turner, B. L. 1994. Synopsis of Mexican and Central American species of Stachys (Lamiaceae). Phytologia 77: 338-377.
Stachys is a large genus with a worldwide distribution variously estimated to house 200-300 species, most of these occurring in the Old World. According to Turner (1994), about 60 species are native to North America, although a number of Eurasian species (ca 10 species) are now introduced into the region and are likely to persist in disturbed areas. Six species are native to Texas, one of these (S. floridana ) relatively rare.
Key to Texas Stachys & Species Descriptions
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