Borassus flabellifer L.

Siwalan (Borassus flabellifer) is a palm up to 15-20 meters tall of the Arecaceae family, native to India, distributed as far as Papua New Guinea and Africa. As a multipurpose tree, siwalan produces sap for sugar, fruit for consumption, and leaves for crafts across East Java, Bali, and Nusa Tenggara. Siwalan is traditionally believed to care for the digestive system and regulate blood sugar levels.

Siwalan grows in lowlands, coasts to mountains (0-800 m above sea level). Adapts easily to dry regions. Optimal temperature ± 30°C, average rainfall 500-2,000 mm/year. Grows ideally in hydromorphic alluvial soil, old gray alluvial, yellow gray, red latosol, and reddish-brown latosol.

• Stem single, cylindrical, sturdy, upright, straight, blackish bark color.
• Leaves fan-like, round, stiff, palmate, grayish-green. Sheath and petiole edges have irregular black thorns.
• Flowers female sometimes branched while male branches a lot. Milky white flower color, clustered, embedded on its cob.
• Fruit clustered in a bunch, about 20 fruits, round with a diameter of 7-20 cm, blackish-brown skin. Each fruit has 3-7 pieces of clear white fruit flesh and covered by a thick, hard shell.

• Propagated by seed.
• Seed sowing is done by soaking the seed in warm water for 24 hours, and scarifying the seed coat so it germinates quickly.

Flavonoid, alkaloid, saponin, tannin, carotenoid, β-carotene, steroid, triterpenoid, propanediol acetate, benzenediol acetate, propanediamine.

Cares for the digestive system, treats diarrhea, cares for liver and kidney function, maintains skin health, regulates blood sugar levels, improves fertility, treats erectile dysfunction (low libido), removes stress.

Lonta (Minangkabau), Ental, Siwalan (Sunda, Java, and Bali), Taal (Madura), Dun tal (Lombok), Jun tal (Sumbawa).