Perennial, foetid, herbs; stems twinning, covered with short stiff, spreading hairs; leaves opposite, broadly ovate, acuminate, cordate at base, ciliate on margin, velvety pubescent; petioles long; flowers in axillary raceme or corymbose cymes; pedicels filiform; sepals-5, small, ovate, acute, ciliate, glandular within; corolla greenish white or yellowish with pink tinge, lobes-5, spreading, broadly ovate, overlapping to right, with long hairs outside, corona white, 2 seriate, outer membranous, annular, 5-10 lobed or cuneate; inner of 5, erect, laterally compressed scales, spurred at back, produced above in long, free, often fimbriate tips; stamens 5, adnate to corolla tube, filaments connate in the column; anthers appendages membranous; pollinia solitary in each anther cell, pendulous, waxy; follicles lanceolate, beaked, clothed with long, soft spines, 5-7.5 cm long; seeds ovoid, densely pubescent.