Purple-stemmed Tall Aster (Swamp Aster)

Symphyotrichum puniceum

KeystoneLarval hostBird foodPollinator plant

Growing it

When	Flowers August to September
Type	wildflower
Sun	Full sun, partial shade
Water	Medium, high
Soil	pH 5.5–7.5
Hardiness	zone 3–7
Mature height	1.8 m
Mature spread	0.9 m
Spacing	0.6 m
Years to maturity	2
Bloom	Aug–Sep
Flower colour	Purple not verified, a genus-level estimate
In bloom	August September
Native to	AB, SK

lance-shaped leaves about 8 cm long

Where it has been recorded

BothSpecimensObservations

95 squares of about 28 km, each holding at least one record. A square is not a claim that the plant grows throughout it, and an unshaded square is unrecorded rather than empty. Darker squares hold more records, which follows roads and towns as much as it follows the plant. 51 herbarium specimens and 108 field observations this project may redraw. A filled dot is a pressed sheet somebody can re-examine; a hollow ring is a photograph identified by community agreement. Where the dots are dense is where people have looked, not where the plant is commonest, and empty ground is unsurveyed rather than unoccupied. How this map is made.

Which ecoregions the records fall in

Mid-Boreal Uplands central AB / SK: 57 records, high confidence
Aspen Parkland central AB / SK: 56 records, high confidence
Boreal Transition central AB / SK: 44 records, high confidence
Peace Lowland north AB: 11 records, medium confidence
Western Alberta Upland central AB: 11 records, medium confidence
Wabasca Lowland north AB: 5 records, low confidence
Slave River Lowland north AB: 3 records, low confidence

These are counts of records collected somewhere in the region, which is the resolution of the evidence: the map above shows where inside it. A region with 3 records is not the same claim as one with three hundred, so the count travels with the region. A region missing from this list means nobody has recorded it there, which is not the same as the plant being absent. Records within 900 m of a border count for neither side, because the border is not drawn finely enough to say which one they are on. Source: GBIF occurrence search + PRESERVED_SPECIMEN pass, retrieved 2026-08-24. Boundaries digitised from the National Ecological Framework for Canada v2.2 (Ecological Stratification Working Group 1995), simplified to about 900 m for display: an outline is accurate to roughly a kilometre, not to the metre. How these counts are made.

See every observation, live and current, on GBIF or iNaturalist.

Documented animals

60 documented relationships.

nectar for

A Leafcutter Bee Specimen records from iNaturalist.org
American Bumble Bee Specimen records from iNaturalist.org
American Lady Specimen records from iNaturalist.org
Andrena hirticincta Specimen records from iNaturalist.org
Aphrodite Fritillary Specimen records from iNaturalist.org
Arctic Fritillary Specimen records from iNaturalist.org
Atlantis Fritillary Specimen records from iNaturalist.org
Autographa precationis Specimen records from iNaturalist.org
Bicoloured Sweat Bee Specimen records from iNaturalist.org
Black-shouldered Drone Fly Specimen records from iNaturalist.org
Ceratina calcarata Specimen records from iNaturalist.org
Clouded Sulphur Specimen records from iNaturalist.org
Colletes compactus Specimen records from iNaturalist.org
Confusing Bumble Bee Specimen records from iNaturalist.org
Drone Fly Specimen records from iNaturalist.org
Eastern Calligrapher Specimen records from iNaturalist.org
Eristalis flavipes Specimen records from iNaturalist.org
Feltia herilis Specimen records from iNaturalist.org
Half-black Bumble Bee Specimen records from iNaturalist.org
Halictus ligatus Specimen records from iNaturalist.org
Helophilus fasciatus Specimen records from iNaturalist.org
Lasioglossum coriaceum Specimen records from iNaturalist.org
Meadow Fritillary Specimen records from iNaturalist.org
Melanchra assimilis Specimen records from iNaturalist.org
Meliscaeva cinctella Specimen records from iNaturalist.org
Melissodes druriellus Specimen records from iNaturalist.org
Milbert's Tortoiseshell Specimen records from iNaturalist.org
Monarch Specimen records from iNaturalist.org
Northern Amber Bumble Bee Specimen records from iNaturalist.org
Northern Paper Wasp Specimen records from iNaturalist.org
Orange Sulphur Specimen records from iNaturalist.org
Orange-legged Furrow Bee Specimen records from iNaturalist.org
Painted Lady Specimen records from iNaturalist.org
Pearl Crescent Specimen records from iNaturalist.org
Peck's Skipper Specimen records from iNaturalist.org
Polygonia progne Specimen records from iNaturalist.org
Red Admiral Specimen records from iNaturalist.org
Red-belted Bumble Bee Specimen records from www.bumblebeewatch.org
Rhingia nasica Specimen records from iNaturalist.org
Spotted Cucumber Beetle Specimen records from iNaturalist.org
Syrphus rectus Specimen records from iNaturalist.org
Tawny-edged Skipper Specimen records from iNaturalist.org
Tricoloured Bumble Bee Specimen records from www.bumblebeewatch.org
Vespula consobrina Specimen records from iNaturalist.org
Vespula maculifrons Specimen records from iNaturalist.org
Viceroy Specimen records from iNaturalist.org
Yellow-banded Bumble Bee Specimen records from iNaturalist.org
Yellow-collared Scape Moth Specimen records from iNaturalist.org

pollen for

Agapostemon texanus Robertson 1929
Ammophila procera Robertson 1929
Brachysomida nigripennis Robertson 1929
Colletes simulans Robertson 1929
Epuraea truncatella Robertson 1929
Halictus ligatus Robertson 1929
Liris argentatus Robertson 1929
Megachile latimanus Robertson 1929
Myospila meditabunda Robertson 1929
Sarcophaga sinuata Robertson 1929
Snowberry Clearwing Robertson 1929
Syrphus torvus Robertson 1929

Also worth knowing

Safety

Toxicity not assessed, absence of a warning is not a guarantee of safety

Buying it

About $8–$16 per plant (estimate), usually stocked by garden centres. Estimate (herb default); AB retail as of 2026

Where these numbers came from

Flower detail: not verified, a genus-level estimate