A few young trees in the Arboretum are designated as endangered or threatened species in Canada. Although far from their native habitat and preferred climate, these plants are relatively isolated here from diseases and other threats, which may aid in their conservation. For example, butternut, an eastern Canadian species, is designated as endangered primarily because of a fungal disease, butternut canker.
Endangered and threatened Canadian species:
Common Name and threat
Red mulberry - endangered in Ontario and nationally; habitat loss, hybridization with non-native species.
Kentucky coffeetree - threatened in Ontario and nationally; deforestation.
Butternut - endangered in Ontario, Quebec, and New Brunswick; habitat loss.