Start this quest by talking to Doctor Camden, who can be found on the Docking Bay/Common Area of the Nexus, near hydroponics. He’ll task you with finding plant samples on various planets throughout the Heleus Cluster. Eos, for its part, has only one such plant worth seeking out. Simply fast travel to The Golden Wastes Forward Station and drive northeast to find a search area, then play "hot-and-cold" until you find the "Heleus Flora" you’re after. Easy-peasy.