Willughbeia edulis

Willughbeia edulis is a vine species bearing tropical fruit in the family Apocynaceae.

Taxonomy
Its species epithet edulis comes from Latin which means "edible". In fact, it is one of the rare climbing plants of Southeast Asia of which the fruits are eatable.

Description
It is a yellow sour edible fruit found in: India, Indo-China (Cambodia, Myanmar, and Isan (northeastern) with Chanthaburi Province of Thailand as well as Vietnam) include Peninsular Malaysia. It may be known under a number of synonyms including "Willughbeia cochinchinensis".

After its reddish lenticelled stems are excised, they exude a milky latex which produces a rubber called chittagong. The roots can be used as a red dye and it may be used medicinally in parts of Asia including Cambodia.

Vernacular names
Local names include: kuy (គុយ) in Cambodia; gedraphol, laleng-tenga, bel-tata in India; dton-kuy (ต้นคุย), kuiton (เถาคุย), kreua (เครือ), and katong-katiew (กะตังกะติ้ว) in Thai; bak yang-pa (บักยางป่า) in Isan dialect. talaing-no in Myanmar; and guồi in Vietnamese.

Kubal madu in Indonesia refers to a similar edible relative, W. sarawacensis.