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Blue Ash
Fraxinus quadrangulata
Location in Ontario
Blue Ash is a rare
Carolinian Tree
that grows in Lambton County, Point Pelee, Pelee Island, Middlesex
County and Elgin
County.
Blue Ash grows on floodplains and
rocky outcrops.
COSEWIC (Committee on the
Status of Endangered Wildlife in Canada) Status:
Blue Ash is identified as a
Threatened species. This is due to its limited range in Canada, loss of habitat
and the effects of Emerald Ash Borer.
COSEWIC: Blue Ash
Blue Ash in fall colour of greenish-yellow,
University of Guelph Arboretum
Genus Fraxinus
Ash
trees have opposite compound leaves. Ash can be monoecious or dioecious depending on the species.
Seeds are contained in a single winged samara (a seed in a papery tissue). Ash
wood is valued for its strength and hardness. Black, Red and White Ash grow in
Ontario, as well as two Carolinian species, Pumpkin Ash and Blue Ash.
Unfortunately, the Emerald Ash Borer has killed millions of Ash trees (see the
Tree Diseases
page). Black Ash has been the most susceptible to the insect, while Blue Ash
shows some immunity.
TREE FACT:
Ash and Hickory are similar with compound leaves, but Ash leaves are opposite
while Hickory leaves are alternate.
TREE FACT: A spring rhyme, referring to which leaves
appear first;
Oak before Ash, you get a splash.
Ash before Oak, you get a soak. |
In the Landscape
Blue Ash is a small, slow growing tree, reaching
20 metres and living to 150 years. It is a lovely tree with
distinctive winged branches, and pretty purple
flowers in the spring. Blue Ash is at risk to the Emerald Ash Borer, but has
shown some resistance to it.
TREE FACT:
When the outer bark of Blue Ash is rubbed off,
there is a bluish inner bark. This was used to make blue dye by Native
people and early settlers.
This Blue Ash is just starting to
turn its greenish-yellow autumn colour.
 Leaves:
Blue Ash leaves have 5-11 leaflets which are coarsely toothed,
long and pointed. Leaves turn greenish-yellow to light yellow
in the fall. |
 Bark:
The bark is gray and scaly, without the diamond pattern of other Ashes. Branches
are ridged on four sides, leading to the name "quadrangulata". |
 Flowers:
Unlike the other Ashes, Blue Ash is
monoecious with perfect flowers.
The flowers are small and purple coloured, and appear in early spring before the
leaves. They are wind pollinated. |
 Fruit:
Seeds, which are
samaras, form in summer, and fall off in early autumn; however some seeds
persist into winter. Seed production is variable, but usually occurs every 3 to
4 years, once the tree has reached 25 yef age. |
Wood
Blue Ash wood is hard and heavy, but not as heavy as White Ash.
It is darker in colour and sold as White Ash.
Specific Gravity: 0.64
Janka Hardness: 1290 lb
Wood Comparison
Chart
Genetics
Blue Ash is diploid. It does not form hybrids.
Mature bark of Blue Ash
Blue Ash is not included in the
United States Forest Service Silvics Manual.
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