Lindernia

Annual or perennial herbs, some aquatic; stems erect to procumbent, simple or branched, quadrangular. Leaves opposite, decussate, sometimes in basal rosette, rarely grouped at apex, sessile or petiolate, variously shaped from ovate to linear, entire or somewhat crenate to dentate, rarely floating; venation usually palmate. Flowers solitary, axillary, or in terminal racemes, pedicellate or sometimes subsessile; pedicels accrescent, sometimes deflexed in fruit. Calyx tubular, 5-lobed; tube +/- turbinate at base, somewhat 5-ribbed or -winged; lobes shallow or extending almost to base. Corolla tubular, bilabiate; tube cylindrical or somewhat campanulate above; upper lip erect, broad, concave, entire or emarginate to deeply bifid, exterior in bud; lower lip larger, spreading, with 3 broad, subequal, rounded lobes. Stamens usually 2 (upper) + 2 staminodes (lower), rarely 4 fertile, didynamous; upper pair arising at top of corolla tube, included in upper lip, with filaments short, straight to arched, linear; lower pair arising +/- in corolla throat, with filaments usually longer, recurved or geniculate +/- at base, usually with large appendage or swelling there, rarely without, then curving inwards above, sometimes truncate +/- at top of appendage; anthers bithecate, free or contiguous; thecae divaricate and often confluent at apex; staminodes 0. Nectary disc-like at base of ovary. Ovary bilocular, ovoid, oblong or subfusiform; ovules many; style filiform, slightly widening above; stigma shortly bilamellate, lobes stigmatic within, touch-sensitive. Fruit an ovoid to long-ellipsoid, septicidal capsule. Seeds many, ovoid, elliptical or cylindrical; testa with thin-walled epidermis cells; endosperm alveolate or sometimes smooth and somewhat furrowed or ridged. x = 9 (7, 8, 10, 11, 12, 13, 15) (polyploidy).