It is prohibited to remove and reduce to possession or maliciously damage or destroy endangered plants on Federal lands. For private lands, it is illegal to collect, damage, or destroy endangered plants in violation of a state law including state criminal trespass law. According to https://www.fs.fed.us/wildflowers/Rare_Plants/conservation/lawsandregulations.shtml#:~:text=It%20is%20prohibited%20to%20remove,including%20state%20criminal%20trespass%20law.

It is prohibited to remove and reduce to possession or maliciously damage or destroy endangered plants on Federal lands. For private lands, it is illegal to collect, damage, or destroy endangered plants in violation of a state law including state criminal trespass law. According to the U.S. Forest Service