All plants, common or rare, have evolved in association with their physical and biological environment to form functioning ecosystems. Both the individual species and the ecosystems represent reservoirs of biological diversity. In recognition of the importance of maintaining maximum biological diversity, rare plants, which are especially vulnerable because of their limited occurrence, receive legal protection at the federal and state levels.
The federal Endangered Species Act of 1973 (16 U.S.C. 1531-1544, 87 Stat. 884), as amended by Public Law 93-205, was passed by Congress and signed by President Richard Nixon in December 1973. The act authorizes the determination and listing of species of plants and animals as endangered and threatened and prohibits unauthorized taking, possession, sale, and transport of endangered species. In addition, the Endangered Species Act provides for the conservation of ecosystems upon which threatened and endangered species of fish, wildlife, and plants depend.
There are six federally listed plants occurring in Pennsylvania; two are listed as endangered and four as threatened. Of the six, four are believed to be extirpated in the state. Enforcement of the Endangered Species Act as it applies to terrestrial and fresh water species is under the jurisdiction of the U.S. Fish and Wildlife Service.
At the state level, the designation of endangered, threatened, and rare plants of Pennsylvania and their protection began with the passage of the Wild Resources Conservation Act of 1982 (P.L. 597, No. 170 (32 P.S. 5301-5314)). This program considers the rarity of plants within the state; species that are rare in Pennsylvania may be common elsewhere. The implementing regulations (Pennsylvania Code, Title 17, Chapter 45) have been amended once to update the lists of classified species and a second revision is currently in preparation.
The Wild Resources Conservation Act defines the status categories, and prohibits the collecting, picking, taking, destruction, or mutilation of plants classified as endangered or threatened by anyone other than the landowner. The regulations include a process for the issuance of permits that can be obtained for scientific studies. Plants listed as rare, vulnerable, undetermined, or special population do not receive protection. The state rare plant program is administered by the Pennsylvania Natural Heritage Program.