This one is Murdannia striatipetala Faden.
Under the title
New Taxa of Murdannia (Commelinaceae) from Sri Lanka
Author(s): Robert B. Faden
Novon, Vol. 11, No. 1 (Spring, 2001), pp. 22-30
Distribution northern Sri Lanka and southern India.
If possible then please ask him exact locality of same. I think either it is from Tambaram, Nungambakam, or Chinghput Guindy. Please confirm.
Thank you.