Ontario Wildflowers website

Whorled Aster
Oclemena acuminata
(formerly Aster acuminatus)

Whorled Aster (Oclemena acuminata) Other common names: Mountain Aster, Sharp-leaved Aster, Whorled Wood Aster

Other scientific names: Aster acuminatus, Aster divaricatus

French names: Aster acuminé

Family: Composite Family (Asteraceae)

Group: Asters

Distinctive features: Woods. Short plant. Has what appear to be whorls of leaves. Flowers in a globular cluster at top of plant. Flower petals (rays) not straight like other asters.

Similar species:
  •   Flat-topped White Aster (Doellingeria umbellata) - Leaves are narrower.

  •   Large-leaved Aster (Eurybia macrophylla) - Has large basal leaves, and all of its leaves are not in a whorl.

Flowers: Summer, Autumn;  White;  7 or more parts (petals);  2.5-4cm in diameter. Ray flowers: white or purple-tinged.

Leaves: Alternate, Simple;  Leaves appear to be in a whorl. Upper leaves are larger than lower leaves. Coarsely toothed, long-pointed.

Height: 30-80 cm (11-31 in)

Habitat: Forests;  Woods.

Lifespan: Perennial.  

Books: Newcomb's Wildflower Guide: 456    Peterson's Field Guide to Wildflowers: 94   

Native/Non-native: Native

Status: Not all that common in Ontario - very common in eastern Canada.

Notes: This is a unique Aster that is very easy to identify.

Photographs: 13 photographs available, of which 5 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Whorled Aster (Oclemena acuminata)

Here is the overall shape and form of the plant. The flowers are in a roughly globe-shaped cluster at the top of the plant. The plant itself is not very tall -- up to only about one foot tall.

Whorled Aster (Oclemena acuminata)

A view from above. Note how the flowers spread out.

Whorled Aster (Oclemena acuminata)

A close-up view of two flowers.

Whorled Aster (Oclemena acuminata)

Note the whorled aspect to the leaves in this photo.

Whorled Aster (Oclemena acuminata)

A "grove" of Whorled Asters. They may grow solitary or in colonies like this. These photos were taken in New Brunswick and Nova Scotia in mid-September. In Ontario this Aster only occurs in a small part of far southeastern Ontario, close to Quebec.

Range map for Whorled Aster (Oclemena acuminata)

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)