Buttercups.

!!All credits will be in the authors note!!

A young girl finds herself suddenly in an unfamiliar area, a long way away from home. Having no other choice she wanders into what seems like some run down lab, and finds another girl who ends up going on the long journey of getting out of the forest with her, with the intentions to protect her. But soon enough, the longer they go along, flowers start to randomly appear on the teens body. Sometimes where she got injured. These yellow flowers showed no mercy, and would soon consume her energy the longer it took.
At first she went along for her own benefit, but soon she realizes that not only is her time with the flowered girl running short, but she's also fallen in love.

(i'll admit, i could've at least been more original with the type of flower. oops.)