Pisonia alba.

Botanical name: 

Pisonia alba Span. Nyctagineae. Tree Lettuce.

East Indies, Malay and common in the gardens about Madras. In taste, the leaves somewhat resemble lettuce, but Wight says, to his taste, it is but an indifferent substitute.

Sturtevant's Edible Plants of the World, 1919, was edited by U. P. Hedrick.