Bignay – a tropical ‘cranberry’
A few years ago a local gardener gave us a small fruit tree which we could not identify. She used a local name, which was not present anywhere on internet or in Smitinand’s book on Thai plant names. Since there are numerous undocumented village names, we just had to wait for the flowers to make a proper ID. The flowers just came out, and it turned out to be: bignay (Antidesma bunius, Euphorbiaceae/Phyllanthaceae).
‘Bignay’ is a commonly used name from the Philippines, but the plant is native from India to Australia. One Chiang Mai name is ‘mamao dong’.
There are 18 species of Antidesma in Thailand of which six occur here in the north. As usual with tropical plants, what you hold in your hand does not entirely fit the description. I used both Flora of Thailand and Forest Trees of Northern Thailand to key it out. The floras claim male and female flowers are kept on different plants, but although on separate branches, the Dokmai Garden plant has both flowers! The floras claim the number of stamens are 3-4, ours has 5. Still, the male flowers have no stalks, which is a bignay characteristic. Its long, up to 20 cm, absolutely glabrous mature leaves with a pointed leaf tip are also typical of bignay. Since this is an appreciated fruit since prehistoric times I guess there are many local and undescribed varieties. Having a tree with both male and female flowers ensures the owner fruit from one individual only (a male would be fruitless), which saves space or gambling. At Dokmai Garden the male flowers emit a putrid smell (smells dead duck) which attracts carrion flies (Calliphoridae).
I have never seen it for sale in the Thai markets, but it is commonly sold in Indonesia. The fruits can be eaten raw or processed into juice or jelly. The flavour is somewhat related to cranberry. The young leaves are edible too, but the bark is said to be toxic.
Text and Photo: Eric Danell
Stalked female flowers (top) and sessile male flowers (bottom). April 12, 2011.
Fruits, July 21, 2011.