Herbaceous root-parasites, devoid of chlorophyll, scapigerous, often fleshy and covered with scale-leaves only. Inflorescence in racemes or spikes, rarely 1-flowered. Bracts scaly, ± like the scale-leaves; bracteoles present or absent, 2, much narrower than bracts, usually free, rarely slightly to conspicuously connate with calyx-tube. Flowers hermaphrodite, hypogynous, zygomorphic, blue, violet, yellowish to brown. Calyx 2-4 (-5)-lobed or toothed, sometimes evidently 2-segmented, rarely spathaceous, persistent, scaly. Corolla often bilabiate, lobes subequal to unequal. Stamens 4, epipetalous, in 2 subequal pairs, anthers mostly connivent; filaments filiform, often hairy at the base, included, rarely subexserted; anthers 2-celled (rarely 1 cell imperfect and spurred). Ovary superior, 2(-3)-carpellary, syncarpous, 1 (-2)-locular, with numerous ovules on (2-)4(-6) parietal placentae; style simple, often long with curved tip and ± 2-lobed, capitate stigma. Fruit an ovoid to oblong capsule, 1-celled, dehiscing into 2 incompletely separating valves, glabrous, usually many-seeded; seeds very small, endospermous with minute, undifferentiated embryos.