Symphyotrichum puniceum (Purple-stemmed Aster)
|Also known as:||Red-stem Aster, Swamp Aster|
|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|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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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:
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.
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 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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Photos by K. Chayka taken at Vadnais/Snail Lake Regional Park, Ramsey County.
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