L., Sp. Pl. 580 (1753).
Derivation: Greco-Latin name for some species of the genus; from Greek stachys, spike; alluding to the dense inflorescence of some species.
Synonymy: Not Applicable
Common name: None
Annual or perennial herbs with quadrangular branches covered with simple hairs; leaves petiolate to sessile, opposite, serrate, crenulate or entire.
Inflorescence a thyrse, with sessile cymose part-inflorescences forming dense clusters around the nodes and with more or less elongated internodes between them only at the base, with bracts leaf-like below but then becoming shorter and insignificant above; sepals more or less equally connate, almost regular, with anterior lobes narrower than the posterior ones, woolly to tomentose with simple but often gland-tipped hairs; corolla 2-lipped, with posterior lip oblanceolate and hooded, with the anterior lip broadly oblong-cuneate with 2 short lateral lobes and a broader 2-lobed central one; stamens 4 fertile, inserted in the throat of the corolla tube; anthers with 2 cells fertile and strongly diverging so that they are above one another in a vertical line, enclosed in the hood of the posterior lip of the corolla; ovary deeply 4-lobed, with each locule with one basal ovule, with a gynobasic style and a terminal 2-fid stigma.
Fruit usually with 4 mericarps each obovoid, rounded or keeled, with the attachment scar circular, basal.
About 300 species mainly throughout tropical and subtropical regions-of the world but also into temperate regions; 2 species naturalised in Australia.
Key to Species:
Not yet available