It looks like this plant can be found in many places where there is plenty of sun. I can see it along the road, on the ground, on the fields, in rubbish dumps, railway embarkments, fences and also old walls. It's scientific name is probably Ruellia tuberosa. I can see it everywhere, except in people's home gardens! But these flowers are quite pretty, hence we should treat it as our Malaysian wildflowers.
Note: Post updated: 23 Nov 11