Symphyotrichum boreale (Northern Bog Aster)

Plant Info
Also known as: Rush Aster
Family:Asteraceae (Aster)
Life cycle:perennial
Habitat:part shade, sun; wet; fens, wet meadows, along shores, swamps, bogs, swales
Bloom season:July - October
Plant height:6 to 36 inches
Wetland Indicator Status:GP: OBL MW: OBL NCNE: OBL
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 7+petals Cluster type: panicle

[photo of flowers] Open, branching clusters of stalked flowers at the top of the stem and arising from the upper leaf axils with 1 to a few to many flowers per plant. Flowers are about 1 inch across with 20 to 50 narrow petals (ray flowers) and a yellow center disk that turns purplish with age. Ray color is white to pale blue or pinkish.

[photo of bracts (phyllaries)] The bracts (phyllaries) surrounding the base of the flower are in 4 or 5 layers, hairless except for a few minute hairs around the edge, very narrow, sharply pointed often with a spot of purple at the tip, and usually of varying lengths, with the outer phyllaries shorter than the inner and sometimes flaring a bit. Flower stalks are hairless or with lines of hairs, and with 1 to a few small leaf-like bracts below the flower.

Leaves and stems: Leaf attachment: alternate Leaf attachment: basal Leaf type: simple

[photo of leaves] Leaves are mostly ascending, lance-linear, 1 to 6 inches long, mostly less than ¼ inch wide, toothless or with a few small teeth, hairless except for sparse hairs on the midvein on the underside and minute hairs around the edge. Basal leaves are broader, more variable in shape, have winged, sheathing stalks, and wither away by flowering time along with the lower stem leaves. Mid and upper stem leaves are stalkless and nearly clasping.

[photo of stem with a line of hairs] Stems are single or multiple from the base, erect to ascending, green to reddish, unbranched except in the flowers, hairless in the lower plant with lines of short hairs on the mid and upper stem and into the flowering branches.

Fruit: Fruit type: seed with plume

Fruit is a dry seed with a tuft of white hair to carry it off in the wind.


Found primarily in wetland habitats, Northern Bog Aster is often a pretty spindly plant. It most closely resembles Panicled Aster (Symphyotrichum lanceolatum), which has proportionately broader leaves up to ¾ inch wide, smaller flowers ¾ inch or less, found in more varied habitats, and is often rather robust with over 100 flowers.

Please visit our sponsors

  • Minnesota Goose Garden

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • ReWild Native Gardens
  • Shop for native seeds and plants at!
  • Shooting Star Native Seeds - Native Prairie Grass and Wildflower Seeds
  • Morning Sky Greenery - Native Prairie Plants
  • Natural Shore Technologies - Using science to improve land and water

More photos

Photos by K. Chayka taken in Pine County. Photos courtesy Peter M. Dziuk taken at Seminary Fen, Scott County, and in Pine County.


Have you seen this plant in Minnesota, or have any other comments about it?

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.