Annual or rarely perennial herbs. Stems slender, erect, prostrate or creeping and rooting at nodes, usually branched, ± quadrangular. Leaves opposite, simple, sessile or petiolate, pinnately or palmately veined, entire or toothed. Flowers solitary, axillary or terminal, or in terminal or axillary racemes or subumbellate clusters. Calyx 5-lobed, 5-veined, either ± shallowly lobed with the lobes spreading or somewhat connivent at maturity, or deeply lobed almost to base; each vein with an obscure to distinct rib or minute wing. Corolla tubular, bilabiate; anterior lip 3-lobed, posterior lip entire to shallowly bilobed. Stamens 4 (either all fertile, or anterior pair with rudimentary sterile anthers), or 2 (posterior, both fertile) with anterior pair reduced to staminodes. Anterior filaments usually spurred or geniculate at or near base. Anthers free or contiguous in pairs under upper lip, thecae divaricate. Style filiform; stigma bilamellate. Ovary obliquely or symmetrically ovoid, oblong or cylindrical to globose. Fruit a septicidal, bilocular capsule, very variable in shape from globose to narrowly cylindrical. Seeds numerous, smooth to alveolate. 

In the currently accepted broad sense as treated here, Lindernia comprises at least 100 species, distributed throughout both Old and New World tropics and subtropics, with tha main centre being tropical Asia; one species (L. procumbens) extending to Europe as far west as southern France. 

In the APG III classification (2009) Lindernia is included in newly established family Linderniaceae.

The genus appears to have been somewhat neglected by collectors in Pakistan as few specimens have been seen. It repays careful study; field notes should include details of flower colour. Nearly all the records are from northern Pakistan; a record of L. anagallis from Thatta, if correct, suggests that efforts to search for members of the genus in wet places in the southern half of the country might bear fruit.