Riedelia Cham.
Shrubs or subshrubs, rarely herbaceous, erect to scandent, usually scabrous with somewhat angular stems. Leaves opposite, rarely whorled, simple, petiolate, usually crenate and rugose. Inflorescence dense or compact, spicate to umbellate, terminal or axillary, pedunculate. Flowers sessile or subsessile, somewhat zygomorphic, small, bracteate, usually red or yellow, sometimes bluish or white. Calyx small, membranous, apex truncate to toothed. Corolla-tube slender, cylindrical or slightly broader above, much exceeding the calyx, with 4-5, short, suborbicular subequal lobes, sometimes obscurely 2-lipped. Stamens 4, didynamous, inserted at about the middle of the corolla-tube; anthers short with parallel lobes. Ovary orbicular, 2-loculed with 1 ovule in each locule; style short with subcapitate, oblique stigma. Fruit a drupe, with usually fleshy, hard endocarp, after drying separating into two, 1-seeded pyrenes; seeds exalbuminous.
About 150 species, mostly tropical American, a few in tropical Asia and Africa; only 2 species found here.
Several species are cultivated as garden favourite in tropical and subtropical countries, producing many garden varieties.
