2. Teucrium L., Sp. Pl. 562. 1753. Gen. Pl. ed. 5: 247. 1754; Benth. in DC., Prodr. 12: 745. 1848; Hook. f., Fl. Brit. Ind. 4: 700. 1885; Briquet in Engler & Prantl, Nat. Ptlanzenfam. ed. 1, 4, 3A: 210. 1895; Mukerjee in Rec. Rot. Surv. Ind. 14, 1: 215. 1940; Juzepczuk in Komarov, Fl. URSS 20: 27. 1954; Hedge & Lamond in Notes Roy. Bot. Gard. Edinb. 28: 145. 1968; Rech. f., Fl. Iran. 150: 23.1982.
Perennial, herbaceous or suffruticose herbs. Stems erect or ascending, leafy, with eglandular hairs, or with glandular hairs on inflorescence axis. Leaves petiolate or sessile, not divided, margins subentire to crenate-dentate. Inflorescence of pedunculate cymes or verticillasters, distant or condensed into spikes or heads. Calyx tubular or campanulate, 10-nerved, bilabiate or regular; tube within glabrous or pilose at throat; teeth 5, equal or unequal. Corolla of 1 spreading 5-lobed lower lip (the adaxial lip represented by 2 lobes at the base of the abaxial lip); tube short, not annulate within. Stamens 4, exserted, didynamous; thecae bilocular, becoming confluent, glabrous. Style exserted, not gynobasic; stylar branches unequal or subequal. Nutlets ovoid or obovoid, rounded, with a lateral oblique attachment scar, reticulate-rugose.
A large ± cosmopolitan genus (probably of more than 200 species) distinguished from other Labiate genera by the non-gynobasic style and the apparently unilabiate corolla of one large 5-lobed lower lip. Its closest ally is Ajugo.