Annual, rarely perennial, root-parasitic herbs. Stems stiffly erect, often square. Leaves opposite or nearly so, ± sessile. Inflorescence a spike. Flowers in axils of leaves or in dense heads. Bracts leaf-like or reduced, bracteoles 2. Calyx tubular, 5-lobed or with 5 (rarely 4) teeth. Corolla with a narrow tube, sharply bent above middle, expanded above; the upper (2) lobes erect, lower (3) lobes spreading. Stamens 4; anthers strictly 1-thecous. Fruit a cylindric or ± ovoid capsule. Seeds minute. Worldwide: 40 species in the Old World tropics and South Africa Caprivi: 5 taxa. |
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