Herbs, perennial, glabrous or pubescent, from stout, ± woody taproots. Stems erect to reclining, often clambering through other vegetation, unarmed, with glutinous bands on internodes. Leaves subsessile to long petiolate, unequal in size in each pair; blade thin or thick and slightly fleshy, base ± asymmetric. Inflorescences terminal and axillary, pedunculate, racemose; bracts deciduous, 1 at base of each pedicel, distinct, lanceolate, thin, translucent. Flowers bisexual, chasmogamous and/or cleistogamous; perianth of cleistogamous flowers forming low dome atop basal portion; perianth of chasmogamous flowers slightly bilaterally symmetric, funnelform, strongly oblique, constricted beyond ovary, tube flared, limbs 5-lobed; stamens 5 (fewer in cleistogamous flowers), exserted; styles exserted beyond anthers; stigmas capitate. Fruits clavate, ± gibbous abaxially, often gently incurved adaxially, stiffly coriaceous; ribs 10, not well defined, with or without interrupted ridges or tubercules, glabrous.