Stems scarcely twisted, long creeping, producing rootlets from nodes. Petiole slightly shorter than blade; leaf blade deltate-ovate to ovate, to 6 × 4 cm, herbaceous, base rounded to cordate, apex acuminate. Flowers axillary, usually 1 per node; bracts 0-3, scalelike. Calyx tube campanulate, 7-10 mm, slightly keeled; lobes 5, linear-subulate to lanceolate, nearly as long as tube. Corolla whitish to pale blue, narrowly campanulate, 3.5-4 cm, deciduous before fruit maturity. Style 1-1.3 cm, included in corolla tube. Ovary subsessile, 0.8-1.2 cm. Fruit fusiform, subsessile. Seeds black, triquetrous, wingless.
Home