B. acutangula or Indian Oak is a plant from the Lecythidaceae family native to Afghanistan, Pakistan, India, Bangladesh, Myanmar, Laos, Cambodia, Vietnam, Thailand, Malaysia, Indonesia (Kalimantan, Sulawesi, Sumatra), the Philippines, Singapore, Sri Lanka, Papua New Guinea, and Northern Australia. It is an important medicinal plant in India and is used in various Ayurvedic formulations for the treatment of various ailments. All parts of the plant have been widely used since ancient times in traditional medicine, where the species holds an important position for various pathologies and its components are being studied for possible use in official pharmacopoeias. In addition, B. acutangula is also often used by people as a vegetable (young leaves), fish poison (bark), wind protection plant, and wood source (in shipbuilding, cabinet work, and carts).

B. acutangula is found scattered along riverbanks and lakes in evergreen and deciduous forests, as well as in seasonally inundated floodplains and freshwater wetlands, swampy locations, rocky or sandy shores at elevations from sea level to 400 m above sea level. It grows well in a variety of soil types, including heavy clay soils, and prefers permanently moist but well-drained soils, with positions in full sun or partial shade. B. acutangula is tolerant of drought and waterlogging. However, it cannot tolerate long dry seasons and temperatures approaching 0 °C.

• The taproot is fibrous.

• The stem is highly branched and has vertically fissured, furrowed, brown-gray bark. The central wood is pink to reddish-gray.

• The leaves are unifoliate, alternate or scattered, elliptical to oblong, with a rough and mostly smooth surface, deep green in color, and pinnately venated. The leaf apex is pointed, the base is tapering. The leaf margins are wavy, finely toothed, and the petiole is short (0.4-1.5 cm long). The scale leaves (cataphylls) are triangular to linear. The leaves may partially fall during prolonged dry periods.

• The flowers have pendulous, arm-length flower stalks. Each stalk bears up to 75 flowers that bloom at night. The flowers are small but showy, dark red, and fragrant. Each flower has 4-5 (usually 4) petals and numerous fibrous stamens that are dark pink to red, with 4 semicircular green sepals.

• The fruit is a dry, 4-angled or oblong-ovate capsule, tapering at the tip, fibrous, and corky with a spongy interior that allows it to float and be dispersed by water. Each fruit is 2-6 cm long and 1-3 cm wide, and contains a single seed. Ripe fruit is brown.

• The seeds are black and ovoid.

• Propagation is by seed and stem cuttings.

• It is best sown immediately after maturity in a position under full light. About 90% of fresh seeds germinate.

• Relieves fever, treats diarrhea and digestive disorders (colic, bloating, etc.), worms, epilepsy, malaria, relieves coughs, colds, asthma, pneumonia, bronchitis, headaches, jaundice, liver disorders, spleen disorders, treats boils, wounds and skin infections, leprosy, arthralgia (joint pain), dysmenorrhea (painful menstruation), back pain, gonorrhea (pus in the urine), eye inflammation (ophthalmia). Health tonic to overcome weakness, improve blood circulation and regulate the menstrual cycle, mouthwash for gum problems. Seeds are rubbed on the chest or eaten with ginger to induce vomiting and expel respiratory mucus. Has activity as an antimicrobial, antipyretic, antimalarial, anti-inflammatory, antioxidant, antirheumatic, analgesic, antidiarrheal.

• Triterpene saponins, acutangulosides A-F, acutanguloside D-F methyl esters, single triterpene aglycones, tanginol, barrinic acid, barringenic acid, barringtogenic acid, tangulic acid and acutangulic acid, terpenes, flavonoids, tannins, steroids, glycosides, barringtogenol B, C and D, 9-Octadecanoic acid, betulin-3-caffeic acid, amyrin, 3,3'-dimethoxy ellagic acid, dihydromyticetin, gallic acid, bartogenic acid, stigmasterol.