This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Herbs or shrubs, with small entire leaves, sometimes with smaller ones fascicled in their axils, and bracted purple flowers in dense terminal or axillary clusters. Calyx campanulate, mostly 10-nerved, 5-toothed, naked or rarely villous in the throat. Corolla-limb 2-lipped, the upper lip erect, flat, entire or emarginate, the lower spreading, 3-cleft. Stamens 4, connivent under the upper lip of the corolla; anthers 2-celled, the sacs parallel or divaricate. Ovary deeply 4-parted; style 2-cleft at the summit. Nutlets oblong or oval. [The classical Latin name of the plant.]
About 18 species, the following typical one introduced as a garden herb from Europe, one of doubtful affinity in Florida, the others of the Mediterranean region.
Satureia hortensis L. Sp. Pl. 568. 1753.
Annual, puberulent; stems erect, slender, much branched, 6-18' high. Leaves linear or linear-oblong, short-petioled, entire, acute at both ends, 1/2'-l 1/2' long, 1"-2" wide; clusters 3"-5" in diameter, terminal and in many of the upper axils; bracts linear, small, minute, or wanting; calyx about equalling the corolla-tube, somewhat pubescent, its teeth subulate, about as long as the tube, ciliate; corolla little longer than the calyx; stamens scarcely exserted.
In waste places, New Brunswick and Ontario to Kentucky, west to Nevada. Naturalized or ad-ventive from Europe. July-Sept.