Botany
Kalabua is an aquatic plant. Roots are fibrous. Leaves are extremely variable, with short or long petioles, according to the depth of the water. Blades of the submerged leaves are often narrow; the floating ones, ovate or somewhat rounded, with a rounded or often heart-shaped base, 5 to 20 cm long. Flowers are white, about 2 cm in length. Fruit is oblong, 2.5 to 4 cm long.

Distribution
Widely distributed in the Philippines.
In shallow fresh water of lakes, pools and slow-running streams.
Occurs wild from Tropical Asia to Australia.

Properties
Febrifuge, rubefacient, antibacterial.

Parts used
Leaves.

Uses
Edibility
Fruit is often sought by children.
Petioles and tender leaves used as vegetable.
Folkloric
Leaves used as arm and leg poultices in fever.
Leaves are used as topicals for hemorrhoids.
Others
• Aquarium: Used as aquarium plant.

Studies
• Anti-Tubercular: A clinical trials, extract of Ottelia alismoides cured two cases of bilateral tuberculosis of cervical lymph glands within 3 months. Results suggest O. alismoides to be a promising medicinal herb with anti-tubercular effect.
• Otteliones / Cytotoxicity: Study isolated otteliones A and B from the fresh water plant Ottelia alismoides. The natural products showed remarkable in vitro cytotoxicity against various cancer cell lines.

Availability
Wild-crafted.

Additional Sources and Suggested Readings
(1)
Preliminary study on the anti-tubercular effect of Ottelia alismoides (L.) Pers. / Li H, Qu X, Zhao D et al / Zhongguo Zhong Yao Za Zhi. 1995 Feb;20(2):115-6, 128.
(2)
Otteliones A and B: Potently Cytotoxic 4-Methylene-2-cyclohexenones from Ottelia alismoides / Seif-eldin N Ayyad, Andrew S Judd et al / J. Org. Chem., 1998, 63 (23), pp 8102–8106 / DOI: 10.1021/jo971870a