Mycoheterotrophic (“saprophytic”) herbs; root system composed of a horizontally creeping primary root with side roots, or a star-shaped clump of tuberous roots, or roots coral-shaped and branched; stems simple, less often variously branched. Leaves opposite, lower ones sometimes alternate, slightly connate at base, small and scale-like. Inflorescence a terminal, few- to 30-flowered bifurcate cyme, or plant having a solitary, terminal flower only; bracts and bracteoles similar to leaves. Flowers variously coloured, erect, rarely nodding, (4-)5(-7)-merous, shortly or long-pedicellate, sometimes fragrant; calyx tubular to campanulate, (4-)5(-7)-lobed, persistent, sometimes provided with discoid scales at inner base; corolla actinomorphic, trumpet-shaped to funnel-shaped, (4-)5(-7)-lobed, variously coloured, far exceeding calyx, long-persistent, tube elongate, lobes contorted, spreading to recurved, rarely ascending (V. clavata), acute to obtuse, rarely acuminate (V. pittieri); stamens (4-)5(-7), included, rarely exceeding corolla tube, inserted at various levels below throat, filaments present or absent, anthers free or coherent just below stigma, introrse, dorsi- to basifixed, thecae rarely caudate at base; pollen generally in monads; ovary 1-locular, 2-carpellate, sessile or sometimes borne on a short gynophore, base often provided with 2 opposite glandular marks or ellipsoid glands, sometimes with 2 distinct stipitate glands at base, or eglandular, ovules ∞, anatropous, style filiform, stigma funnel-shaped, capitate, or weakly 2-lobed. Fruit a fusiform to globose capsule, septicidally dehiscing along whole length or in middle only, often indehiscent; seeds ∞, more or less globose or filiform.
Guianas present, Throughout the Neotropics present, tropical W Africa present
A genus with 19 species, 18 of which occur Throughout the Neotropics and 1 in tropical W Africa; 12 species in the Guianas.