Baccaurea motleyana

Rambai (Baccaurea motleyana)
Scientific name	Baccaurea motleyana
Common names	Rambai; mafai-farang; rambi
Genus	Baccaurea
Family	Phyllanthaceae
Order	Malpighiales
Growth form	Evergreen tree
Native range	Thailand, Malaya, Sumatra, and Borneo; wet tropical biome
Mature size	About 15 to 25 m in larger trees; often smaller in cultivation
Climate and site	Hot, humid lowland tropics; rainforest or riparian settings
Soil	Moist, well-drained alluvial or other suitable tropical soil; pH around 5 to 6 is reported
Propagation	Fresh seed; air-layering of female trees; budding or grafting
Fruit	Buff-colored, 2 to 4 cm fruit in racemes from branches and sometimes trunk
Harvest	Thailand: generally July to August; regional timing varies

Rambai (Baccaurea motleyana) is a Southeast Asian fruit tree in the family Phyllanthaceae. GBIF accepts Baccaurea motleyana as the species name and places it in Phyllanthaceae.^[1] Kew lists Thailand, Malaya, Sumatra, and Borneo in its native range and associates the species with the wet tropical biome.^[2] The fruit is eaten fresh and is also used for drinks and pickles.^[3]

Description

Rambai tree with fruit on branches and trunk at the MARDI rare fruit genebank in Serdang, Malaysia.

Rambai is an evergreen tree with a dense crown. Larger trees are described at about 15 to 25 m, although cultivated trees may be smaller. The twigs, petioles, and lower leaf surfaces are velvety; leaves are obovate-lanceolate to elliptical and about 20 to 35 cm long.^[3]

The species is dioecious, with separate male and female trees. Its inflorescences are ramiflorous. Female racemes may be 25 to 60 cm long, and fruit occur in communal strings from twigs and main branches and, to a lesser extent, the upper trunk.^[3]

The fruit is generally buff-colored, smooth to thinly puberulous, and about 2 to 4 cm in diameter. Translucent white pulp surrounds a variable number of seeds, and flavor may range from acid to sweet and palatable among trees and selections.^[3]

Cultivation

Soil and water

Rambai is a wet-tropical lowland tree associated with rainforest and occasional riparian settings. Cultivation descriptions include alluvial soil, yellow clay, sand, and limestone where moisture is available and drainage remains adequate. A pH around 5 to 6 is given as preferred, with a broader reported range of about 4.5 to 6.5.^[4]

Use a moisture-retentive but aerated root zone rather than permanently stagnant soil. The reported soil range is a cultivation guide, not a fixed chemical limit; drainage and steady moisture are both important for a tree from wet tropical habitats.^[2][4]

Sun and humidity

Full sun or light shade is suitable in the cultivation account, consistent with a hot, humid lowland environment.^[4] Provide bright exposure with humid air and enough airflow to keep the crown from remaining continuously wet.

Seasonal changes

Rambai is evergreen in its tropical cultivation description. In Thailand, the general fruit season is July to August, while rainfall patterns in other parts of the range shift flowering and harvest timing.^[3] Keep root moisture steady during active growth and fruit development, while maintaining drainage through wetter periods.

Propagation

Fresh seed is described as germinating in a few days. Because male and female flowers occur on separate trees, seedlings do not preserve a known fruiting female; air-layering a selected female is a more direct way to retain fruiting sex and fruit quality. Budding and grafting are also described for rambai.^[3][4]

Flowering, fruiting, and harvest

Rambai fruits develop in racemes on older wood, branches, and sometimes the trunk. A tree may carry green and buff-colored fruit at the same time as individual fruit mature. The Thai general season is July to August, but local rainfall, tree sex, selection, and site can shift flowering and harvest.^[3]

Harvest fruit when it is fully colored and ripe. Pulp flavor varies from acid to sweet among trees. Where a fruiting selection is available, clonal propagation preserves a chosen fruit-quality type more reliably than seed propagation.^[3]

Fruit and uses

Ripe rambai is eaten fresh. The pulp can be crushed for a drink, sweetened and diluted, or pickled for use with curries. The fruit is small and seed-bearing, and pulp commonly adheres to the seed.^[3]

In the Thai context, very large fresh consumption is associated with stomach upset; this is a food-use caution rather than a medicinal claim.^[3]

Photos

References

• ↑ [1] GBIF species match: Baccaurea motleyana, accessed 2026-09-28.

• ↑ [2] Kew, Plants of the World Online: Baccaurea motleyana, accessed 2026-09-28.

• ↑ [3] Suranant Subhadrabandhu, Under-Utilized Tropical Fruits of Thailand, FAO RAP Publication 2001/26, section 6 “Mafai-farang (Baccaurea motleyana)”, accessed 2026-09-28.

• ↑ [4] Useful Tropical Plants: Baccaurea motleyana, accessed 2026-09-28.

Image credits

• Fruits of Baccaurea motleyana (Phyllanthaceae).JPG — NusHub, CC BY-SA 3.0; cut-open rambai fruit showing pulp and seeds. Attribution to NusHub and cropsforthefuture.org is requested on the file record.
• Tree of Baccaurea motleyana (Phyllanthaceae).JPG — NusHub, CC BY-SA 3.0; rambai tree with fruit on branches and trunk.
• Mass fruiting of Baccaurea motleyana (Phyllanthaceae).JPG — NusHub, CC BY-SA 3.0; heavy fruiting throughout the canopy at MARDI Serdang.
• Young fruits of Baccaurea motleyana (Phyllanthaceae).JPG — NusHub, CC BY-SA 3.0; young rambai fruit hanging on the tree.