Baccaurea macrocarpa, known commonly as tampoi, is an evergreen tropical fruit tree in the family Phyllanthaceae. It is native to the primary lowland rainforests of Southeast Asia, particularly throughout Borneo, Sumatra, and the Malay Peninsula. The genus name Baccaurea is derived from the Latin bacca ("berry") and aurea ("golden"), referring to the appearance of the fruit, while the species epithet macrocarpa means "large-fruited." Historically, this species has been a critical wild-foraged resource for indigenous communities throughout the Malay Archipelago, where the trees are often maintained as semi-wild components of forest-edge ecosystems rather than being subjected to intensive orchard cultivation.

The tree is dioecious, meaning male and female flowers grow on separate individuals, and it can reach heights of up to 25 meters. It is characterized by a dense, spreading crown and smooth, greyish-brown bark. The most striking feature of the tree is its cauliflory—the botanical phenomenon where the fruit clusters develop directly from the trunk and the main woody branches rather than from the outer canopy twigs. The fruit itself is a globose, thick-skinned capsule, typically brownish or yellowish in color, measuring 4–7 centimeters in diameter. When cracked open, it reveals several large, white, cream-colored, or occasionally reddish arils that tightly surround the seeds. Baccaurea macrocarpa thrives in humid, lowland tropical climates with high rainfall and is typically found in well-draining, nutrient-rich forest soils.

The tampoi is highly valued in regional gastronomy for its unique balance of sweet and tart flavors. The fleshy, juicy arils are primarily consumed fresh, offering a texture that is often compared to a mangosteen or a sweet, tangy grape. The pulp is succulent, refreshing, and cooling, making it a favored snack during the humid tropical afternoons. In some regional culinary traditions, the pulp is also processed into jams, fermented into mild fruit wines, or incorporated into savory sambals where its acidity can provide a bright, zesty contrast to pungent fermented shrimp paste or fiery chili. Because the thick, woody rind protects the interior well, the fruit is relatively easy to transport and store compared to more fragile tropical berries.

Nutritionally, Baccaurea macrocarpa is a source of dietary fiber, carbohydrates, and moderate amounts of Vitamin C. Its biochemical profile is defined by a diverse array of secondary metabolites that are typical of the Phyllanthaceae family, including specialized triterpenoids and phenolic acids. The fruit contains varying concentrations of organic acids, primarily citric acid and malic acid, which contribute to its characteristic tartness. In traditional Malay and Dayak folk medicine, decoctions made from the bark and roots are used as an astringent to treat digestive issues, and the sap or fruit extracts have been applied topically for certain skin conditions. Modern research is beginning to explore the antioxidant potential of the fruit's pulp and the antimicrobial properties of its bark extracts.