Much like the plants in Brinstar in Super Metroid, Cyrlic trees are sometimes placed indoors (such as in the Arboretum) so it is possible that they do not use photosynthesis, but perhaps other means such as chemosynthesis, or both, like some bacteria. This connection may also signify that the Chozo planted the vegetation in Brinstar (which may be related to the Cyrlic tree) since they once lived on Zebes. They were not named in Metroid Prime, but were later in Metroid Prime 3: Corruption.