It seems  Physalis angulata of family Solanaceae

Please check the following link for usefulness of Physalis angulata.

http://tropical.theferns.info/viewtropical.php?id=Physalis+angulata

There are two species of Physalis, P angulata and P minima and it seems both the species are present in the photograph. The following link may be followed for better identification

http://www.banglajol.info/index.php/BJB/article/download/1731/1641/

Physalis angulata is a good guess. But it is better  if scientists may upload photographs in generative stages, either flowers or fruits for confirming the identity.

Scientific name: Physalis angulata

 Physalis angulata  is used to treat malaria, toothache, liver ailments including hepatitis, rheumatism, and is considered a diuretic and relaxant. Plant infusions are taken to treat gonorrhoea, indigestion, nephritis and fever.

i think N.N.Mohanan,s view point is valid.to me it looks to be Dahlia of Family Compositae.

Physalis angulata L. is correct answer by Dr. Arvind.

Dr Nilay Borah appears to be correct when he says that there are two species of Physalis that are the largest plants in the picture.