Black Ash

Species Information

Black Ash or Wisqoq are broad-leafed hardwood trees belonging to the Olive Family (Oleaceae). They are generally 18 to 21 m tall with large spreading or ascending branches. The leaves are opposite and compound with 7 to 11 oval to lance-shaped leaflets; leaflets have no stalk. Clusters of rusty hairs are apparent where leaflets join petiole. Trunk is gray in colour and smooth to corky on young trees and scaly on mature trees. Wisqoq usually produces inconspicuous flowers that appear in the spring before leaf-out in clusters at branch tips. Fruit is a winged, flatten, single seeded samara that is borne in terminal or lateral branches.

Distribution

Globally, Wisqoq ranges from western Newfoundland west to southeastern Manitoba, and south to Illinois and northern Virginia. In Nova Scotia, Wisqoq is currently known from all counties, except Yarmouth, Shelburne and Richmond counties. Historic records exist for Yarmouth and Shelburne Counties.

Habitat

In Nova Scotia, Wisqoq is typically found in poorly drained areas often along swampy woodland stream and river banks with moving water.

Biology

Wisqoq are wind-pollinated and flower before leaf-out in late May or early June. Seeds are produced at 1 to 8 year intervals and are dispersed from October to the following spring. In Nova Scotia, total seeds produced yearly per tree ranged from 2 to 1500. Wisqoq seeds stay in dormancy between 2 to 8 years and seedlings are poor competitors. Wisqoq can sprout vigorously from stumps after cutting; most regeneration is occurs through this means. Wisqoq is slow growing, moderately long-lived with a typical longevity of 130 to 150 years. Age or size at maturity is unknown. Wisqoq is particularly susceptible to fungal diseases, poor growth and stunting.

Population sizes and trends

Wisqoq is reported from 35-40 sites in 11 counties of Nova Scotia since 2000; other unconfirmed sites exist. Due to their sparse nature, it is likely that more populations will be discovered in the future with additional search effort. Mature individuals are poorly known and only 12 are known to occur, although it is likely that more are present. Total number of known specimens in Nova Scotia is approximately 1000.

Limiting factors and threats

Habitat loss and alteration of wet areas is likely the most prevalent threat for Wisqoq at present in Nova Scotia. Historical threats may have included over-harvest for cooperage. Other current threats may include selective harvest of mature Wisqoq trees for crafts, transplanting trees from non-native stock and die back. Although not yet documented in Nova Scotia, serious future threat for all ash species exists from the exotic beetle, the Emerald Ash Borer, which is spreading quickly in Ontario and Quebec and severely decimating populations of ash in its path.

Special significance of the species

Wisqoq has unique features that enable it to be peeled into thin strips and bent which make it a preferred species for basketry, furniture, interior finish and as a veneer. Aboriginal Peoples of northeastern Canada and the United States historically and currently use Wisqoq in basket making, including the Mi’kmaq of Nova Scotia. Several Wisqoq hybrids and cultivars are used in landscaping.