Annual to perennial herbs, usually hairy and often glandular. Lvs mostly alternate, entire or 1-2-pinnate. Infl. a simple or branched cyme of few to many fls. Calyx lobed almost to base. Corolla rotate, campanulate or tubular, generally white, blue, or purplish, deciduous or persistent, with corolla scales attached in pairs to corolla tube at base of filaments. Stamens included or exserted; filaments sometimes adnate to corolla scales. Style 1, 2-fid, sometimes divided almost to base. Capsule 1-locular or nearly 2-locular; seeds 2-numerous on the 2 linear placentae. Seeds reticulate, pitted or transversely corrugate.