Pennsylvania’s Rare, Threatened, and Endangered Plants
home to approximately 3,000 plant species, roughly two-thirds of those are
considered native to the commonwealth. Of these native plants, 582 are classified by DCNR, with 349 considered rare, threatened, or endangered in Pennsylvania.
The list of classified plants is available in the PA Code, Title 17, Chapter 45.
rare plants are currently classified as follows:
Why Are Native
species make up a plant community or an ecosystem. The balance of an ecosystem
can be impacted by the loss of a species. This can have negative effects on all
species, plants, and animals in an ecosystem.
are important to native wildlife and pollinators, and provide greater ecosystem
services (such as flood prevention and soil stabilization) than non-native
plants can indicate the health of an ecosystem. Plants can be rare because their
habitats are uncommon or have become degraded. When a common plant becomes
rare, it often indicates that a habitat needs help.
Makes Plants Rare?
can threaten populations of plants and cause them to become rare. These include
situations that limit gene flow among populations, loss of individuals, or
competition for resources.
Some of the
most common threats to plants in Pennsylvania include:
Habitat loss and fragmentation, due to development or conversion of habitat
Invasive plants displacing native plants
Creation of more edge habitat, increasing the threat of invasive plant species
Selective browsing by white-tailed deer or other wildlife may prevent plants from reproducing
Over-collected by humans of showy, edible or medicinal plants
is DCNR Doing about Rare Plants?
DCNR collects and analyzes data about
plants. When the Department has enough information to change a species’ status,
it does so through a regulation change. By classifying plants, DCNR
communicates the level of protection a plant needs.
DCNR provides recommendations
for active management for these species to preserve and enhance their
populations. DCNR provides information through the following:
Pennsylvania Conservation Explorer -- users have access to plant community information
- Pennsylvania Natural Diversity Inventory environmental review -- provides review for potential impacts to threatened and endangered plant species; available through the PA Conservation Explorer
- Education on invasive plants -- provides management information for this threat to native plants
- Information on using native plants -- provides alternatives to potentially invasive landscaping plants, and benefits native pollinators
- Updating classifications -- maintains an up-to-date list of plants that need protection in Pennsylvania. More information about classification updates can be found on the right
Rare Plants on DCNR Lands
From open areas
to mature forests, DCNR lands host a wide range of plant communities and the
department considers the diversity of plants in its management approach. DCNR uses planning to protect manage common and rare plants on DCNR lands.
Important plant communities are protected or designated for plant conservation
such as natural and wild areas, wild plant sanctuaries, or high conservation
These sites are managed using appropriate techniques and
practices to promote and improve growing conditions for rare plants or may
limit certain activities in other areas to conserve sensitive plant
species are a major threat to plant communities as they can out-compete native
species, alter habitats, and disrupt life cycles of native invertebrates.
Invasive species management on DCNR lands is important to limit the impact of
invasive plants on native plant communities. Also, part of that approach is
supplemental plantings with native plants.
Here’s what DCNR is doing to benefit
native wild plants:
Planting and Seeding Guidelines (PDF) -- These guidelines focus on native plantings for DCNR lands, which lessens the threat of invasive species.
- Invasive Plant Management Plans -- DCNR has developed several tiers of planning to deal with invasive species, at the Department level, bureau, and site specific levels.
- Pollinator Planting Guidelines (PDF) -- These recommendations help revegetation projects benefit native pollinators.
- Planning and designation of important plant habitats -- DCNR uses special designations to protect some exemplary populations and communities of rare plants in wild plant sanctuaries, wild areas, natural areas, and high conservation value forests.
authority from two acts -- one gives authority to survey ecological features and
the other to classify and manage native wild plants.
The Wild Resource Conservation Act (PDF) (WRCA) established a procedure for the conservation,
classification, and protection of wild plants and charged the Department of
Environmental Resources with that responsibility.
This act required the
Department of Environmental Resources to conduct investigations on native wild
plants regarding populations, distribution, habitat needs, limiting factors and
other biological and ecological data to classify the plants and determine
Later, the Conservation and Natural Resources Act (Act 18) of 1995 split the Department of
Environmental Resources into the Department of Environmental Protection and
created the new Department of Conservation and Natural Resources.
Act 18 gave
the WRCA responsibilities to the DCNR. Pennsylvania code Title 17 Chapter 45,
the Conservation of Pennsylvania native Wild Plants, is DCNR’s regulatory
effort to carry out the responsibilities of the WRCA.
Since the DCNR Bureau of
Forestry’s mission includes the conservation of native wild plants, the
responsibility of implementing Chapter 45 and the WRCA has been the bureau’s.
The Listing Process
has a robust process of public participation, data gathering, and input. Anyone in Pennsylvania can petition DCNR to
change a plant’s status.
for making changes to the list of classified plants involves stakeholder
groups, particularly the Pennsylvania Biological Survey’s Vascular Plant
Technical Committee (VPTC -- the technical committee of the Pennsylvania
Biological Survey focusing on plants), and the Rare Plant Forum (RPF -- the
public function of the Vascular Plant Technical Committee).
Through public meetings and technical committee meetings, in addition to DCNR’s own
investigations, information is obtained on plants to aid in determining classification
The VPTC, made up of experts in
the botanical field including academics, consultants, natural history museums,
and non-profits, meet twice a year to make recommendations on species listings
The RPF includes experts and amateur
enthusiasts, and meets once a year to discuss trends and present new research on
plants, including species taxonomy, inventories or field surveys, and genetic
Some of the
data that is used to determine plant statuses include:
The regulation, Conservation of Native Wild Plants, gives DCNR the
status definitions used to classify plants that are in decline in
Pennsylvania Endangered -- A classification of plant species which are in danger of extinction throughout most or all of their natural range within this commonwealth, if critical habitat is not maintained or if the species is greatly exploited by man. This classification also includes populations of plant species that have been classified as Pennsylvania Extirpated, but which subsequently are found to exist in this commonwealth.
Pennsylvania Extirpated -- A classification of plant species believed by the department to be extinct within this commonwealth. The plants may or may not exist outside this commonwealth. If plant species classified as Pennsylvania Extirpated are found to exist, the species automatically will be considered to be classified as Pennsylvania Endangered.
Pennsylvania Rare -- A classification of plant species which are uncommon within this commonwealth because they may be found in restricted geographic areas or in low numbers throughout this commonwealth.
Pennsylvania Threatened -- A classification of plant species which may become endangered throughout most or all of their natural range within this commonwealth, if critical habitat is not maintained to prevent their further decline in this commonwealth, or if the species is greatly exploited by man.
Pennsylvania Vulnerable -- A classification of plant species which are in danger of population decline within this commonwealth because of their beauty, economic value, use as a cultivar or other factors which indicate that persons may seek to remove these species from their native habitats.
Special Concern Population -- A classification that is composed of colonies, groups or single individuals of a plant species that the department has determined to be a unique occurrence deserving protection. Among the factors that may be used to classify a plant population within this category are the existence of unusual geographic locations, unisexual populations or extraordinarily diverse plant populations.
Tentatively Undetermined -- A classification of plant species which are believed to be in danger of population decline, but which cannot presently be included within another classification due to taxonomic uncertainties, limited evidence within historical records or insufficient data.
Unlisted -- Plant species which are native to this commonwealth, presently capable of sustaining their populations successfully, not in need of protection currently and currently not included in classifications under this chapter.
Wild Plants -- Naturally occurring native flora, except those commonly considered an agricultural commodity, including green and non-green species or subspecies, variety or a part, product, seed or progeny thereof.
Can You Do at Home?
There are some
things you can do at home to help native wild plants.
First, leave native wild plants where they are. Picking flowers means the plant will not go to seed. For plants with very few individual, this can be detrimental. Take pictures, but leave the flowers in their habitats.