Diascia

Herbs, annual or perennial; stems usually slender, diffuse or erect, sometimes rigid. Leaves opposite or rosulate at base, with upper ones sometimes alternate, mostly petiolate, rarely sessile, variously shaped, from linear to suborbicular or sometimes oblanceolate to obovate, margins usually variously dentate, sometimes repand, pinnatifid or pinnatisect, rarely entire, usually glabrous; upper leaves often somewhat different. Flowers solitary, axillary or subfasciculate, or in terminal racemes, bracteate. Calyx 5-lobed; segments lanceolate, ovate or oblong, somewhat imbricate, slightly accrescent in fruit. Corolla usually tubular, bilabiate; tube very short, sometimes invaginated or obsolete; limb flattened, rotate or concave; posterior lip bi- or quadrifid, exterior in bud; anterior lip trifid or simple, middle or only lobe often emarginate, lobes +/- rounded; throat usually produced below anterior lip into 2 (rarely 1 or 0) pits, pouches, or spurs wherein oil-secreting trichomes are found in several species; windows (patches of translucent material) usually present, either at base of lateral corolla lobes, associated with openings to pouches or spurs, or central at base of upper lip, and there sometimes split into 2 contiguous or separate parts; very rarely windows absent; central posterior window varies in form from +/- flat to pouched or drawn out into a short hollow cone. Stamens (2)4, didynamous, arising in mouth of corolla tube; posterior pair with anthers; anterior pair usually bent near base, passing round posterior pair and coming to be in posterior position, rarely with anthers 0; some or all filaments broadened, sometimes with a projecting appendage; anthers bithecate but 1-celled as thecae confluent, usually cohering in pairs; staminodes 0(2). Ovary bilocular, usually ovoid; ovules many; style simple, terete, shorter or somewhat longer than ovary; stigma simple or capitate. Fruit an obliquely ovoid, subglobose or elongated, obtuse, septicidal capsule, not or scarcely compressed; valves inflexed at lateral margins, entire or emarginate. Seeds many, brown, usually curved, often with hollow on ventral side filled with +/- cup-shaped or bulbous outgrowth of seed coat with various apertures, usually ribbed and not winged, sometimes pitted or reticulate and/or winged, rarely straight and/or smooth to granulate or muricate. x = 9 (B-chromosomes-1 report, aneuploids, polyploidy).