It is a dicotyledonous and angiosperm shrub, which is fast growing. It has many cultivated varieties and it can grow up to 6m tall. It is the national flower of Malaysia.
Its leaves are margin, narrow to broad ovate, about 7-10cm long. The border of the leaf is toothed (serrated). The leaves can be used as medicine for parotitis.
It blooms most of the year. The flowers are opening trumpet-like and very conspicuous. It is about 10 cm in diameter; the number of spreading petals is 5 or multiples of 5. It has a long staminal tube, which is red, orange or yellow in colour. It can be single-petalled or double-petalled. The ovary always consist of 5 carpels. Petaloid carpels may be present in the cultivated double-petalled varieties. Its flowers can be eaten.
Fruits are rarely developed; it is a dark brown woody capsule of five parts.
