Can you confirm the identity of this plant growing on the northeastern coast of Brazil? I’m told it is called batata-da-praia, or batata-do-mar (beach or sea potato). Does that mean it’s edible?
This is Ipomoea pes-caprae, probably the subspecies brasiliensis, given the location. It is pantropical, found along the beaches of the tropical regions of the Atlantic, Pacific, and Indian oceans. (It produces air-filled seed capsules that float and drift in water, contributing to its wide distribution.)
Common names in English include railroad vine (referring to the ‘tracks’ created by its stoloniferous habit of spreading along the ground’s surface, sometimes over 100 feet), goat’s foot (translation of the botanical species name, given for the hoof-like leaf shape), beach morning glory (since it is in the morning glory family, Convolvulaceae), and beach hops (because of the vining habit).
Cooked roots, stems, and leaves have been eaten in small quantities as a famine food, and it has a history of medicinal uses. However, it is not a major food source like its cousin, the sweet potato (Ipomoea batatas). Toxic Plants of North America (Burrows & Tyrl, 2013) considers this species of Ipomoea to be of toxicological concern.