Diagnostic features:
(i) Aerial plant parts are hairy.
(ii) Leaves alternate, becoming opposite in floral region.
(iii) Calyx 5, gamosepalous, persistent.
(iv) Corolla 5, gamopetalous.
(v) Stamens-polyandrous and epipetalous.
(vi) Gynoecium-bicarpellary syncarpous.
