Ontario Wildflowers website

Azure Aster
Symphyotrichum oolentangiense
(formerly Aster oolentangiensis)

Azure Aster (Symphyotrichum oolentangiense) Other common names: Sky Blue Aster

Other scientific names: Aster oolentangiensis, Aster azureus

Family: Composite Family (Asteraceae)

Group: Asters

Distinctive features: Sparse azure blue ray flowers, Loose and open growth form. Leaves feel like fine sandpaper. Resembles Heart-leaved Aster, but the leaves are different, and is more open.

Similar species:
  •   Heart-leaved Aster (Symphyotrichum cordifolium) - More compact, leaves deeply lobed at base.

  •   Smooth Aster (Symphyotrichum laeve) - Leaves rubbery and smooth.

  •   Fringed Blue Aster (Symphyotrichum ciliolatum) - Larger leaves.

Flowers: Summer, Autumn;  Blue/Violet;  7 or more parts (petals);  Rays wide, relatively.

Leaves: Alternate, Simple;  Feel like fine sandpaper. Few teeth or toothless, not deeply lobed like those of Heart-leaved Aster. Lower leaves are long arrowhead-shaped.

Height: 50-100 cm (19-39 in)

Habitat: Fields and Open Areas, Meadows;  Dry areas, prairie-like areas, edges of woods. South Ontario only.

Grows in Sun/Shade: Sun

Lifespan: Perennial.  

Books: Peterson's Field Guide to Wildflowers: 354   

Native/Non-native: Native

Status: Not overly common, but not rare.

Notes: This Aster is hard to describe except in terms of what it's not. Generally it looks like an open Heart-leaved Aster, but without the distinctive leaves of that species. The flowers are smaller and more compact, the ray flowers are "chunkier". This would be one of the later Asters for a novice to learn.

Photographs: 137 photographs available, of which 10 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Azure Aster (Symphyotrichum oolentangiense)

Azure Aster flowers. the rays are somewhat wider than some other Asters.

Azure Aster (Symphyotrichum oolentangiense)

Closeup of Azure Aster flowers.

Azure Aster (Symphyotrichum oolentangiense)

Sometimes the flowers are rather crowded.

Azure Aster (Symphyotrichum oolentangiense)

But usually they are sparsely arranged.

Azure Aster (Symphyotrichum oolentangiense)

A single flower.

Azure Aster (Symphyotrichum oolentangiense)

Azure Aster leaf. The leaves feel like fine sandpaper. This is a distinctive feature of this species.

Azure Aster (Symphyotrichum oolentangiense)

Basal rosette of leaves.

Azure Aster (Symphyotrichum oolentangiense)

The overall shape/form of Azure Aster is of a sparse open plant.

Azure Aster (Symphyotrichum oolentangiense)

Azure Aster (Symphyotrichum oolentangiense)

Range map for Azure Aster (Symphyotrichum oolentangiense)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)