English : Periwinkle
Hindi : Sdabahar
Malayalam : Nithyakalyani, Shavakkottappacha, Ushamalari
It is an evergreen subshrub or herbaceous plant growing 1 m tall. The leaves are oval to oblong, 2.5–9 cm long and 1–3.5 cm broad, glossy green, hairless, with a pale midrib and a short petiole 1–1.8 cm long; they are arranged in opposite pairs. The flowers are white to dark pink with a darker red centre, with a basal tube 2.5–3 cm long and a corolla 2–5 cm diameter with five petal-like lobes. The fruit is a pair of follicles 2–4 cm long and 3 mm broad.In the wild, it is an endangered plant; the main cause of decline is habitat destruction by slash and burn agriculture.It is also however widely cultivated and is naturalised in subtropical and tropical areas of the world. It is so well adapted to growth in Australia, that it is listed as a noxious weed in Western Australia and the Australian Capital Territory and also in parts of eastern Queensland.