Symphyotrichum puniceum (Purple-stemmed Aster)

Plant Info
Also known as: Red-stem Aster, Swamp Aster
Family:Asteraceae (Aster)
Life cycle:perennial
Habitat:part shade, sun; moist soil; swamps, bogs, along shores, edges of woods, thickets, wet meadows
Bloom season:August - October
Plant height:1 to 7 feet
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] Branching clusters of stalked flowers at the top of the stem and arising from upper leaf axils. Flowers are 1 to 1½ inches across with 30 to 60 slender petals (ray flowers) and a yellow center disk that turns reddish purple with age. Ray color is very pale violet to bright blue-violet. The bracts (phyllaries) surrounding the base of the flower are in 4 to 6 layers, very narrow, hairless to sparsely hairy, pale green with a lance-linear green tip that is usually spreading. Flower stalks are up to 1 inch long, hairy, with a few narrow, leaf-like bracts below the flower.

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

[photo of leaves] Leaves are mostly dark green, 2 to 8 inches long and 1/3 to 1¼ inch wide, tapering to a sharp point at the tip, with fine widely spaced teeth and a prominent center vein. Leaf bases are stalkless and typically have a pair of small lobes that clasp the stem. Basal leaves are lance to spatula-shaped with winged, sheathing stalks and wither away by flowering time along with lower stem leaves.

[photo of stem and leaf hairs] Leaf texture is bristly with short hairs along the central vein on the underside, and the lower surface is typically paler than the upper. Stems are single or multiple from the base, mostly erect, usually become reddish purple as the plant matures and are sparsely to densely covered in stiff white hairs, though sometimes becomes hairless or nearly so on the lower stem.

Fruit: Fruit type: seed with plume

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


There are currently 2 recognized varieties of S. puniceum: var. scaricaule is only in a few southern states, and var. puniceum, described above is present throughout the eastern half of the US and all across Canada. There is much debate whether Glossy-leaf Aster (Symphyotrichum firmum) is a separate species or a variant of S. puniceum. It is generally characterized by paler, nearly white flowers, stems mostly hairless or hairy in lines, and a tendency to form large colonies from long, creeping rhizomes.

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More photos

Photos by K. Chayka taken at Vadnais/Snail Lake Regional Park, Ramsey County.


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

Posted by: Kaye - Brooklyn Park
on: 2011-07-15 10:27:33

Actually, I am not sure if what I have/see is a purple-stemmed aster, but this seems to be the closest (when looking at the pictures you have uploaded). The leaves are the same, the color, too, and most everything about the flower depicts the purple-stemmed variety. So, I know that it's an aster. However, the petals are a lot more profuse, thinner. Does anyone know what kind of aster this would be?

Posted by: K. Chayka
on: 2011-07-15 10:53:36

Kaye, there are similarities between purple-stemmed aster and New England aster. It typically has more numerous and narrower rays as you describe, and is also usually a deeper purple color. The leaves tend to be shorter and a bit more blunt at the tip than purple-stemmed. Maybe that was it.

Posted by: Bob - the Zim-Sax Bog, St. Louis County
on: 2012-08-21 20:56:21

I've come across an Aster that might be the same as what Kaye is referring to. The one I found has most of the same characteristics as listed for the Purple-stemmed Aster except this one has a green stem (though the plant may just be young), has 14 slender, pale violet to blue-violet petals (with one flower approaching 15), the bracts are flush and the leaves, while finely toothed, are only up to 4-5 inches long and 1-2 inches wide, maybe more. Each leaf is also positioned directly under a new branch. The other asters listed don't seem to have the finely toothed leaves combined with the dense, fine hair that gives a coarse feel.

Posted by: K. Chayka
on: 2012-08-21 21:30:43

Bob, if the flowers only have 14 or so rays, it would not likely be purple-stemmed aster, which has at least 30, plus spreading bracts and longer, narrower leaves than you describe. If you have some images of your mystery aster post them on our Facebook page and we'll see if we can give you a confirmed ID.

Posted by: Charles - St. Paul
on: 2015-12-26 08:51:52

Variety scabricaule

Posted by: Ruth HL - Duluth, MN
on: 2017-08-14 10:02:56

We have it growing at the house end of our driveway, up against the woods and near, but not in, a boggy area. The stems are dark reddish-brown and covered with fine white hairs, and the underside of the leaf vein has the fine white hairs characteristic of this plant's leaves. However, the flowers are a paler purple than our New England Asters. We did not plant these, but we have been removing invasives from the property and planting natives over the past few years, and more native plants are just showing up. These are growing with a couple of different kinds of Goldenrod.

Posted by: Gary - Cook, Lake, St. Louis, Carlton counties among many
on: 2018-11-19 19:26:13

Bob (Zim-Sax Bog), who has seen a blue aster with about 14 rays might have found a blue flowered form of Symphyotrichum lanceolatum. I have also found this color form in the same area. Another blue to purple flowered aster in the Zim area is Canadanthus modestus which might be mistaken for New England aster.

Posted by: Renay - Elk River
on: 2022-08-28 16:10:31

Just saw some of this in our old pasture, definitely looks more like this (more petals and pointed leaf ends) than NE aster. Pretty!

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