According to this meme if you bury a body underneath an endangered plant, it is then illegal for law enforcement to dig up the body. Is this true?
The Meme is Incorrect
Law enforcement in the united-states may disturb or dig up plants that are listed as endangered species while unearthing evidence of a serious crime.
16 U.S. Code § 1538 subsection (a) ,(2) provides that:
(2) Except as provided in sections 1535(g)(2) and 1539 of this title, with respect to any endangered species of plants listed pursuant to section 1533 of this title, it is unlawful for any person subject to the jurisdiction of the United States to—
(B) remove and reduce to possession any such species from areas under Federal jurisdiction; maliciously damage or destroy any such species on any such area; or remove, cut, dig up, or damage or destroy any such species on any other area in knowing violation of any law or regulation of any State or in the course of any violation of a State criminal trespass law;
Digging up a member (or members) of an endangered plant species during a legitimate criminal investigation as part of a focused search for evidence would not be to "maliciously damage or destroy" them, nor would it be in "knowing violation of any law or regulation of any State".
This notion (that evidence is safe if buried under endangered plants) misunderstands what is prohibited by the law.
Those plants listed in Schedule 8 are protected by s.13(1)(a) and all others by s.13(1)(b)
s.13(1) [ ... ] if any person—
(a) intentionally picks, uproots or destroys any wild plant included in Schedule 8; or
(b) not being an authorised person, intentionally uproots any wild plant not included in that Schedule,
he shall be guilty of an offence.
However, s.13(3) provides a statutory defence that disproves the claim made in the OP's meme:
s.13(3) Notwithstanding anything in subsection (1), a person shall not be guilty of an offence by reason of any act made unlawful by that subsection if he shows that the act was an incidental result of a lawful operation and could not reasonably have been avoided.
The recovery of a body by the police (or other authorised person) following a suspicious death is a "lawful operation" which may include progressing a criminal investigation, making the deceased available for post mortem or to inform the mandatory coroner's inquest
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