Not many people know this spleen plant (Baccaurea lanceolata) that comes from Kalimantan. Wikipedia states that this plant comes from the genus Baccaurea, belonging to the Phyllanthaceae family.
Lempaung [Baccaurea lanceolate] is a plant that is commonly found in the forests of Sumatra and Kalimantan. It also grows on slopes and riverbanks. The fruit is sour, but dense all year round.
In various regions, this plant has various names. In Sumatra, people call it lempaong, langsat forest, and tegeiluk [Mentawai]. In Kalimantan it is called spleen, ampusu, tamarind pauh, empaong, lampaong, lampawong, lampong, legau fruit, lipasu, nipassu, kalampusu, to lempahong. While in Java, the name is lingso.
Lempaung is a plant in the form of a tree with a height of 3–30 m, and a diameter of 5–60 cm, has 2 houses, with buttressed stems. Young shoots are green to grey-green and brown when dry, branching is terminal and weak. The indumentum has a single hair, while the bark is gray to yellowish, some are greenish-white when fresh. Papagan gray to pale brown, gray when dry, 0.2–3 mm thick, soft, scaly, sometimes smooth; inner bark is pale brown to white, gray, and yellow, 2–3.5 mm thick. The heart of the wood is slightly brownish yellowish.
Leaves single, alternate, spirally arranged, spirally arranged; the base of the leaf edge usually contains glands, the leaf blade is oval to round breech. Male and female inflorescences attached to the stem (cauline), some clustered in abundance. Flowers are arranged along the inflorescence, the color is yellow-reddish, or light brown-whitish, petals, stamens and staminodium numbering 3-5, breech-ovoid to scoop and slightly clustered. The number of flowers is 20-25, the color is brownish yellowish-reddish. Number of petals 4-5, shape ovoid to breech, easily shed; corolla 2–8, reducing; ovary rounded, bear 3 or 4; anthers reddish to yellow. The fruit is rounded to oblong, with 1-4 seeds, purplish or green when it is young, when it is ripe it is green, yellowish, whitish, grayish, brown. The seeds are indented.
Distributed in Thailand and Malesia. In Malesia itself, lempaung is found in Indonesia, one of which is in Sumatra, northern East Java, Palawan, and Borneo. In Borneo, it is found in Serawak, Brunei, Sabah, West Kalimantan, Central Kalimantan, South Kalimantan and East Kalimantan. It grows in neglected primary/secondary rainforest, on mountain slopes and river forests. The soil needed for the growth of clay is clay and rocky. Lempaung grows at an altitude of 1300 meters above sea level, common in the lowlands. Flowering March–December. This plant bears fruit throughout the year, although its fruit is not comprehensive in Indonesia.