There aren't many plants seen in RAGE. Beside some rather neutral flora in different locations and out in the Wasteland and lush mutated vegetation in some areas of Dead City, particularly in Dead City Hospital, there are only three notable plants. Apparently brought to Earth by 99942 Apophis or heavily influenced by the presence of Feltrite and harsh climatic changes, they all have unique properties and can used by Nicholas Raine and other people to create very useful and powerful drugs. Some of them will periodically grow back throughout the course of the Campaign, and some are only available once.
Comet Bloom can be found in some rocky locations, e.g. not far from the Ghost Hideout bridge in the Ghost Territory and near the Authority gate that blocks the way to the Ravine and Authority Bridge elevator. It is used to create painkillers people like Norbu need, and when used in conjunction with a Vial of Blueshine and Bandages, it creates Regenerative Infusion, a potent mixture that greatly boosts regeneration rate.
Desert Spore usually grows in warm places with fertile soil that can provide some cover from wind and direct sunlight to the flower. Many of the 13 Desert Spores (14 with the Wasteland Sewer Missions DLC) are hidden among rocks and/or other plants that can protect them from the Sun and winds, as well as some greedy eyes. Known for its curative properties, it can be used to create most precious Apophis Infusion, the powerful mixture that permanently increases health. Sadly, this very plant is the only one that doesn't regrow over time.
Night Blossom is perhaps the most moisture demanding plant of all three. It usually grows in humid places that can offer fertile soil, clinging to some rocks that can protect it from strong winds, and enjoys duskiness while not being too fearful of sunlight. Many Night Blossoms are found in the Swamp, and those that grow inside of buildings are found not far from water sources, like the one in a restroom in Ghost Hideout, another one in latrine near the Wasted Garage, and yet another one in a locked room in Subway Town that is likely to have all the water it needs from a nearby groundwater conduit. Known to stimulate endorphins, it helps to increase health and is used to create Adrenaline Overdrive and Apophis Infusion.
Although none of these plants existed before 99942 Apophis hit, at least in their current form, they don't look too alien in the future world and apparently have successfully found their niches in the ecosystem. Beside the unusual and wonderful properties, their only strangeness is that none of them seem to need sunlight to grow and bloom.
- It's recommended to check the Comet Bloom and Night Blossom spots periodically after making some notable main storyline progress in order to not miss regrowing plants.