You can get the plant at Wal-Mart, Home Depot, Lowes, Walgreens or a local hardware store. I recommend Lowes!
Drosera are a genus of carnivorous plants in the family droseraceae, which includes the genus dionaea and aldrovanda (venusflytraps).
You have 3 chalenges at the Dock you have to use the Chamealean suit, at rooftops vent you have to be quick and avoud the venusflytraps, and at File X use the Laser pen 1 of the traped agents gave you.