Thymus
noun
Subshrubs with slender branches arising from usually short, sometimes stout, woody stems. Leaves entire or 1-3-serrulate. Verticillasters in dense capitula or spikes. Flowers pedicellate. Calyx tubular-campanulate to narrowly campanulate, 10-13-veined, 2-lipped, throat white hairy annulate; upper lip spreading or straight, 3-toothed, teeth triangular to lanceolate; lower lip 2-toothed, teeth subulate. Corolla tube included or exserted, 2-lipped; upper lip straight, emarginate; lower lip spreading, 3-lobed, lobes subequal or middle lobe longer. Stamens 4, separate; anterior 2 longer, exserted or included; anther cells 2, parallel or divaricate. Style apex 2-cleft; lobes subulate, equal or subequal. Nutlets ovoid or oblong, smooth. Some botanists recognize 300-400 species in Africa, Europe, and temperate Asia; others have suggested that many of these species should be treated as infraspecific taxa of Thymus serpyllum Linnaeus. China has at least 11 species, mainly N of the Huang He. Klokov (Fl. U.S.S.R. 21: 471. 1954) reported that fertile hybrids are common in areas of overlap between some species.