It’s hard to say, I don’t know any styles that fit this exact description but I can give my two best guesses.
Environmental Art - uses natural materials from the art piece’s environment as the media and basis for the artwork. Often used to make a statement about nature or environmental conditions. (think Walter De Maria’s “Lightening Field”)
Art Nouveau - usually an applied art that uses nature-inspired forms but not necessarily made from natura materials. (think Alphonse Mucha’s “Daydream”)
sorry i couldn’t offer something more specific. hope you find what you’re looking for!
