Trees, shrubs, undershrubs or perennial herbs. Leaves exstipulate, simple, alternate, opposite, or whorled, sometimes imbricate and appressed to the stem. Flowers axillary solitary or in terminal or axillary clusters, racemes or panicles, bisexual, actinomorphic or slightly zygomorphic, floral parts situated on or below a fleshy disc. Calyx 4-7-lobed, persistent. Corolla 4-7-lobed, usually gamopetalous, campanulate, saucer--shaped or urceolate, sometimes sepals and petals not distinguishable. Stamens often as many or twice as many as petals; free or adherent at base of corolla,, anthers sometimes spurred; dehiscing by apical pores or slits. Ovary inferior or superior, typically 5, sometimes 4-10-locular; placentation axile; ovules numerous; style often simple; stigma capitate. Fruit capsular; dehiscence loculicidal or septicidal. Seeds minute, numerous, endospermic.
A family of about 50 genera and 1350 species, mostly inhabiting the temperate regions of the northern and southern hemispheres, less often sub-arctic and tropical. In West Pakistan the plants are confined to the mountains in the north.