Rare and Endangered Species

With nearly 1200 acres of land, the Arboretum is dedicated to conservation, the protection of plants, and deeper public understanding of the value, beauty and critical nature of plants in their lives. While most public gardens have conservation efforts, very few gardens are widely known as centers of research and/or conservation.

Oxytropis campestris var. chartacea (Fasset's Locoweed)


The Arboretum is a proud partner with the Center for Plant Conservation (CPC), an organization founded in 1984 that seeks to prevent the extinction of US native plants. As a partner in the CPC, the Arboretum is responsible for leading conservation efforts for seven species, which include an orchid (Platanthera praeclara, western prairie fringed orchid), a Minnesota endemic (Erythronium propullans, dwarf trout lily) and a Wisconsin endemic (Oxytropis campestris var. chartaceae, Fassett’s locoweed).

The work and research for this program involves creating a long-term genetically diverse seed bank of each species as well as developing an understanding of how best to propagate and out-plant each species. The long-term goal of this program is to enable restoration work to be able to be performed with each species with the ultimate objective being successful restoration or preservation in situ. In addition, considering the changing climate, this work will help to preserve the genetic diversity necessary for each species to be able to adapt to climate changes, and will also enhance knowledge regarding how to successfully introduce these plants back into a natural or restored landscape.

The Arboretum focuses on “Ex Situ” conservation, which is the process of protecting an endangered plant outside of its natural habitat, In Situ, or "on site" conservation, preserving a species in its natural habitat, is the highest priority for species conservation, and is found to be the most efficient way of conserving biodiversity because it can preserve not just the species but the entire community and all of the ecosystem processes that support all of the members of the community. While in situ conservation efforts continue to set aside healthy landscapes, these landscapes are being affected, directly and indirectly by human activity, through climate change, water tables, irrigation, ever-encroaching developments, etc. Ex situ conservation can be thought of as an insurance policy in some regards, by backing up the genetics of endangered species we can ensure that if, or when, a species is lost in its natural landscape it can be replaced. 

The Arboretum’s regional leadership for endangered species work has resulted in partnerships with both the Minnesota and Wisconsin Departments of Natural Resources to assist in rescues of endangered species populations that have been under immediate threat.

Endangered Species at the Arboretum

Western Jacob's Ladder (Polemonium occidentale ssp. lacustre)

While the majority of the Arboretum's endangered species are under watch and conservation at the Horticultural Reserach Center (HRC), there is one species open to visitors. Western Jacob's Ladder, or Polemonium occidentale ssp. lacustre, is a native perennial that is closely related to a subspecies of the Rocky Mountains, from which is gets its common name of Western Jacob's Ladder. The species requires wet swamps, primarily associated with cedar and alder. There are only six known populations of Jacob's Ladder, four of which are in Minnesota, and the remaining two in Wisconsin.