Water spinach

Ipomoea aquatica, widely known as water spinach, is a semi-aquatic, tropical plant grown as a vegetable for its tender shoots. I. aquatica is generally believed to have been first domesticated in Southeast Asia. It is widely cultivated in Southeast Asia, East Asia, and South Asia. It grows abundantly near waterways and requires little to no care. Ipomoea aquatica grows in water or on moist soil. Its stems are 2–3 metres or longer, rooting at the nodes, and they are hollow and can float. The leaves vary from typically sagittate (arrowhead-shaped) to lanceolate, 5–15 cm (2–6 in) long and 2–8 cm (0.8–3 in) broad. The flowers are trumpet-shaped, 3–5 cm (1–2 in) in diameter, and usually white in colour with a mauve centre. Propagation is either by planting cuttings of the stem shoots, which will root along nodes, or by planting the seeds from flowers that produce seed pods.

Source: Wikipedia