Once a species is lost, it is gone forever. Nova Scotia has 20 vascular plant Species at Risk. The Harriet Irving Botanical Gardens hold living specimens of six of these species for conservation, education, and research. These species are either protected under the Nova Scotia Endangered Species Act, Canada’s Species at Risk Act, or both.
Water-pennywort (Hydrocotyle umbellata)
Apiaceae – Carrot Family, Endangered (NS) & Special Concern (CA)
Water-pennywort is listed as threatened in Canada and endangered in Nova Scotia. This species in known to occur only in four lakes in Southwestern Nova Scotia; Kejimkujik, George, Springhaven Duck, and Wilson’s lakes. If you’re lucky, you will see it in bloom. You have to look closely, however, as the blooms are very small and delicate. We have not introduced this endangered plant to our outdoor plant collection for fear that it would not survive in this unnatural stream setting; it is held in our experimental garden.
Thread-leaved Sundew (Drosera filiformis)
Droseraceae – Sundew Family, Endangered (NS & CA)
Thread-leaved Sundew is listed as endangered across Canada. The only known location for this species north of Massachusetts is in a select few bogs in Shelburne County, Nova Scotia. This remarkable little plant is one of our 10 native carnivorous plant species, deriving much of its nourishment from the insect world rather than the nutrient-poor soil of the bog. The leaf blades are covered in long hairs that are coated in a sticky substance. Insects land on the leaves and get stuck; then the plant creates enzymes that slowly break down the insect carcass so that its nutrients are available to the plant. This plant is held in our indoor research collection.
Black Ash (Fraxinus nigra)
Olive Family, Threatened (NS & CA)
Black Ash is a medium-to-large tree species that grows in swamps and floodplains across most of the Acadian Forest Region. Its rarity in Nova Scotia, combined with the threat of the invasive and destructive Emerald Ash Borer, have resulted in its current status of threatened. First Nations across this species’ distribution range have used Black Ash for centuries, especially in the production of baskets. Black Ash can be difficult to identify in the field, and its distinguishing features include dark brown and somewhat pointed buds, a fairly corky and non-furrowed bark, and leaflets with abundant and fine teeth all the way to their base. We have a handful of Black Ash trees planted in the native plant habitats at the Botanical Gardens.
Eastern Mountain Avens (Geum peckii)
Rose Family, Endangered (NS & CA)
This species is only found in two places on Earth: a few mountains in New Hampshire and in and near Nova Scotia’s Brier Island. In the mountains, the species grows in wet meadows above the treeline and along cascading rivers, while in Nova Scotia it grows in fens. Although dissimilar in appearance, both habitats are wet, fairly open, cool, and include calcium-rich soils. The flowers have five yellow petals and are in bloom for much of the summer. Eastern Mountain Avens is considered globally imperiled and at high risk of extinction. We hold a small research collection of this plant in our experimental garden.
Rockrose (Crocanthemum canadense)
Rockrose Family, Endangered (NS)
Rockrose occurs in open, dry, sandy areas. The only location that this plant grows in Atlantic Canada is in southern Nova Scotia. Over 97 per cent of its preferred sand barren habitat in Nova Scotia has been lost. This species’ large yellow flowers are very short-lived, opening only on sunny mornings with the petals dropping around mid-day. Its other name, Frostweed, refers to this species’ ability to collect unusually large and eye-catching amounts of frost in early autumn. Efforts to propagate and collect seed from this plant in our experimental garden have been successful. The seed is now stored at Acadia’s Seed Bank.
Eastern White Cedar (Thuja occidentalis)
Cypress family, Endangered (NS)
Cypress Family, Vulnerable (NS) This evergreen tree species is widespread and abundant throughout much of its range but is considered uncommon in Nova Scotia, where it occurs only in several counties near the Bay of Fundy. Eastern White Cedar can grow for up to 1,600 years and is a highly valued species for wildlife and as an ornamental garden tree. It also plays an important role in First Nations ceremonies. In the wild, it mostly grows in wetlands, seepages, and riparian areas. We have young Eastern White Cedar trees planted in our Calcareous Woodland habitat.