Trifolium Hastam

This plant enters a human's ears as dust which is then attracted to the brain due to it's warmth, it's unknown how it moves further into the head though.

Once on the brain, the dust consumed part of the host's brain, replacing it with it's own matter. The host, now under the plants manipulation will act normally.

Once under control, the host's lips and irises will turn green and the plant will grow out of the host's ear with a combination of open three leaf clovers, that absorb the sunlight, and it's sexual organs that disperse more dust. Oddly enough, the sexual organs look like fluffy/grassy wheat seeds. The roots in the brain absorb the water within the host's bloodstream.