Ontario Wildflowers website

Heart-leaved Aster
Symphyotrichum cordifolium
(formerly Aster cordifolius)

Heart-leaved Aster (Symphyotrichum cordifolium) Other common names: Blue Wood Aster, Common Blue Wood Aster

Other scientific names: Aster cordifolius, Aster choralis, Aster finkii, Aster lowrieanus, Aster plumarius, Aster sagittifolius, Symphyotrichum sagittifolium

French names: Aster à feuilles cordées

Family: Composite Family (Asteraceae)

Group: Asters

Distinctive features: Heart-shaped leaves. Flowers in a dense rounded panicle (ie, not flat-topped).

Similar species:
  •   Azure Aster (Symphyotrichum oolentangiense) - leaves of this species are in between Arrow-leaved Aster and Heart-leaved Aster.

  •   Arrow-leaved Aster (Symphyotrichum urophyllum) - leaves not deeply cleft at all.

  •   Large-leaved Aster (Eurybia macrophylla) - leaves much larger, not as deeply cleft. Flowers in a flat-topped head, usually white.

Flowers: Summer, Autumn;  Blue/Violet;  7 or more parts (petals);  1.5cm in diameter. Ray flowers: 8-15, pale blue, blue-violet, rose, or mauve; sometimes white. Disc flowers: 14-20, yellow becoming purple. Flowers are arranged in a rounded panicle in dense clusters.

Leaves: Alternate, Simple, Toothed;  Basal leaves are heart-shaped, with a very deep cleft at the base of the leaf. Upper stem leaves are still somewhat heart-shaped, but without a deep cleft, or have a much shallower cleft - resemble leaves of Arrow-leaved Aster (Symphyotrichum urophyllum). Conspicuously & jaggedly toothed.

Height: 60-90 cm (23-35 in)

Stem: Smooth, many-branched.

Habitat: Forests, Fields and Open Areas;  Open woods and edges of woods.

Grows in Sun/Shade: Shade

Lifespan: Perennial.  

Books: Newcomb's Wildflower Guide: 454    Peterson's Field Guide to Wildflowers: 354   

Native/Non-native: Native

Status: Common.

Notes: This is a fairly easy Aster to identify, and is fairly common. The leaves are distinctive, but they may be confused with the similar species listed above.

Photographs: 148 photographs available, of which 11 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Heart-leaved Aster (Symphyotrichum cordifolium)

The whole plant.

Heart-leaved Aster (Symphyotrichum cordifolium)

The flower head. Note that the flowers are in a rounded panicle. This is in contrast to Large-leaved Aster (Eurybia macrophylla), in which the flower head is flat-topped.

Heart-leaved Aster (Symphyotrichum cordifolium)

A patch of the plants in mid-September north of Sudbury.

Heart-leaved Aster (Symphyotrichum cordifolium)

Here's a more open form of this species.

Heart-leaved Aster (Symphyotrichum cordifolium)

Close-up of the flowers.

Heart-leaved Aster (Symphyotrichum cordifolium)

Note that they are typical Aster flowers in that the discs start out yellow, and gradually turn purple.

Heart-leaved Aster (Symphyotrichum cordifolium)

A typical leaf. Note the jaggedly saw-toothed edges. This is in contrast to Large-leaved Aster (Eurybia macrophylla) flowers, which are not so prominently toothed.

Heart-leaved Aster (Symphyotrichum cordifolium)

Notice the shape of the notch at the base of the leaf - this is distinctive and is a reliable identifying feature.

Heart-leaved Aster (Symphyotrichum cordifolium)

Sometimes the leaves are "stubbier".

Heart-leaved Aster (Symphyotrichum cordifolium)

Heart-leaved Aster (Symphyotrichum cordifolium)

Range map for Heart-leaved Aster (Symphyotrichum cordifolium)

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)