Cardiospermum halicacabum Linn., Sp. Pl. 366. 1753. Boiss., l.c.; Hiern in Hook. f., l.c. 670; T. Cooke, l.c.; Collett, Fl. Siml. 96. 1902; Bamber, P1. Punj. 595. 1916; Jafri, l.c.; D. A. Webb in Tutin et al, l.c.
Annual, sometimes perennial herb, up to 3.5 m tall. Stem and branches slender, grooved, glabrous to sparsely pubescent. Leaves 5-6 cm long; petiole 1.5-3 cm long; leaflets opposite, 1-2 cm long, pinnatisect, terminal leaflet 4-6 cm long, acute to acuminate. Flowers white in 3-7 flowered, axillary cymes; peduncle 5-9 cm long, sparsely pubescent; bracts 2, subulate, 1 mm long; pedicel 0.5-1.5 cm long, lowest pair modified into circinately coiled tendrils. Sepals free, concave, persistent; 2 outer ones orbicular, c. 2 mm long, ciliate; 2 inner ones oblong-ovate, 3-4 mm long, glabrous. Petals obovate, c. 3 mm long, 2 lower ones with a crested woolly scale, 2 upper ones with a large leafy scale. Disc reduced to 2 glands inside the lower petals. Stamens free; filaments compressed, 2 mm long, hairy; anthers 0.5 mm long; pistillode present in male flower. Ovary obovoid, 2-3 mm long, hirsute; style short, pubescent; stigma 3-fid; staminodes 8 in the female flower. Capsule sub-globose or broadly pyriform 3-4 cm wide pubescent. Seeds 3, 1 in each locule, globose, c. 6 mm in diameter, black; aril white, 5 mm broad, cordate.
Distribution: Tropical and subtropical Africa, America, Malacca, Ceylon, India and Pakistan.
The ‘Baloon-vine’ or ‘Heart-seed’ is found up to 1300 m. alt. s.m. It is cultivated as a garden annual for its curious inflated fruit; the green parts are eaten as a vegetable and the roots and seeds are medicinal.