This section is from the book "British Wild Flowers In The Four Seasons", by Thomas Moore. Also available from Amazon: British Wild Flowers.
* Calyx-tube gibbous at the base beneath.
C. Acinos: annual; stems branched, 6-8 inches high, slightly downy; leaves small, narrow-ovate, slightly toothed; flowers pale purple or white, in axillary whorls on short, erect pedicels. - Basil Thyme. - Fields. Fl. July, August.
** Calyx-tube equal at the base.
C. officinalis: stems hairy, ascending or erect, with straggling branches, 1 foot high; leaves broadly ovate, toothed; flowers pinkish-lilac, in small loose cymes, forming terminal, one-sided, leafy panicles; calyx tubular, ribbed, half as long as the corolla, the teeth with long cilia. - Pledges, roadsides, and waste places. Fl. July to September. Mr. Bentham makes the two following plants varieties of this: C. Nepeta: leaves ovate, nearly entire; flower-cymes contracted into loose whorls, the corolla half as long again as the calyx, which is shortly ciliate. - Dry open, sunny banks.
C. sylvatica: stem taller; leaves larger, broadly ovate, sharply toothed; cymes loose, the flowers showy, the corolla fully twice as long as the calyx. - Woods in the Isle of Wight.
C. Clinopodium: stems erect or ascending, branched, softly hairy, 1-2 feet high; leaves ovate, slightly toothed, soft, hairy; flowers purple, in dense cymes, forming compact whorls or heads in the axils of the upper leaves, or at the ends of the branches, surrounded by subulate, hairy bracts. - Wild Basil. - Hedges and woods. Fl. July, August.
 
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