Nemesia

Annual or perennial herbs or undershrubs, sprawling to erect; stems often quadrangular and branched from base, glabrous or pubescent. Leaves mostly opposite, sometimes alternate above, linear or lanceolate to ovate, entire or toothed, sessile or petiolate. Flowers solitary-axillary or in terminal racemes, bracteate, pedicellate, often alternate. Bracts sometimes leafy. Calyx 5-lobed, somewhat accrescent in fruit. Corolla bilabiate, personate, 5-lobed; tube short, extended at front into a dependent spur, pocket or pouch; posterior lip 4-lobed, exterior in bud, with laterals outside both posteriormost lobes and anterior lip; anterior lip 1-lobed, entire or emarginate, with a convex, sometimes papillate palate at its base. Stamens 4, didynamous, arising in mouth of corolla tube; filaments linear, anterior pair usually bent at base round posterior pair and coming to be in posterior position, usually appendaged at base; anthers usually cohering in pairs about stigma; thecae confluent. Ovary bilocular, usually elliptical; ovules many; style short, thick and terete or filiform; stigma simple or bilobed. Fruit a septicidal capsule, usually ovate to urceolate, somewhat laterally compressed; apex rounded to emarginate; valves boat-shaped. Seeds many in 1 or 2 series, usually +/- ellipsoid, more rarely spindle-shaped; wing membranous, entire or interrupted. x = 9 (10-1 report, aneuploids).