Torenia

Annual herbs, sometimes aquatic; stems slender, procumbent, weakly ascending, or erect, simple or branched, quadrangular, usually glabrous, sometimes rooting at nodes. Leaves opposite, decussate, petiolate, ovate to lanceolate, +/- serrate, pinnately veined. Flowers axillary, pedicellate, usually 2-6 together, fascicled or on minute leafless branches, or sometimes solitary; pedicels ebracteolate, somewhat reflexed in fruit. Bracts narrowly linear. Calyx tubular, bilabiate, 5-lobed, narrowly winged along veins, markedly so at fruiting, accrescent; lobes shorter than tube. Corolla tubular, bilabiate, 4-lobed; tube cylindrical below, widening slightly above; upper lip entire, exterior in bud; lower lip larger, with 3 subequal lobes. Stamens 4, didynamous; filaments arising in corolla throat; posterior pair included, with filaments short; anterior pair with filaments longer, arched and connivent under upper corolla lip, each with small boss-like appendage at base; anthers bithecate, usually cohering in pairs; thecae usually confluent at apex. Nectary prominent, saucer-shaped. Ovary bilocular, oblong, dorsiventral, hairy at apex; locules with unicellular hairs within; ovules many; style semiterete, exserted, persistent; stigma of two membranous lobes. Fruit a narrowly oblong-ellipsoid capsule, septicidal or poricidal. Seeds small, many, pale yellow; testa with anchor-like thickening on some epidermal cell walls; endosperm alveolate (bothrospermous). x = 8 (9, 17-1 report each) (polyploidy).