From WikiPilipinas: The Hip 'n Free Philippine Encyclopedia
Gumamela (Hibiscus rosasinensis) is a species of flowering plant found in cultivation throughout the Philippines. Aside from ornamentation, gumamela is being used by some locals as alternative medicine.
 Habitat and Description
Gumamela is a native of the Old World, but is now distributed throughout the tropics.
This plant is an erect, much branched, smooth shrub, 1 to 4 meters in height. The leaves are ovate and 7 to 12 centimeters long, with coarsely toothed margins. The flowers are solitary, axillary, very large, about 10 centimeters long, and 12 centimeters in diameter. The calyx is green and about 2 centimeters long, with ovate lobes. The petals are red, orange, or rose white, obovate, rounded, and imbricate. The staminal tube is slender and longer than the corolla. There are many hybrids of different colored, simple flowers in addition to a few doubles.
Gumamela is largely cultivated in the Philippines as ornamentals for its colorful flowers. It is also planted as a hedge.
In some places in the Philippines, a paste made from gumamela flower buds are applied as a poultice to boils, cancerous swellings and mumps. A decoction of the roots, barks, leaves, and flowers are also used as a skin softener.
In Malay countries, a decoction of the root is said to be used as an antidote for poisons, and as cure for venereal diseases, fevers, and coughs. A solution made from the leaves are also used as a lotion for fevers, while an infusion of the leaves is used to relieve headaches. There have been reports that the bark is being used as an agent to induce or hasten menstruation. It is also very common to see gumamela leaves applied to poultice swellings.
- Quisumbing, Eduardo (1978). Medicinal Plants of the Philippines. Quezon City: Katha Publishing.