Flower

Swamp Aster

Symphyotrichum puniceum

Also known as Purplestem Aster, Red-stalk Aster, Early Purple Aster, Cocash

Swamp asters thrive in saturated soils along marsh edges, fens, and stream banks, standing out in late summer and autumn with brilliant displays of pale violet to blue ray florets. Distinctive stout, bristly reddish-purple stems support branched floral sprays that act as critical late-season nectar stations for migrating butterflies and prepping bumblebees. Stems can form robust, clonal colonies via creeping rhizomes, stabilizing wet ditch banks and saturated meadows against seasonal flooding.

FloweringWetlandPerennial

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Least ConcernConservation status

Key facts

Diet & preyAutotrophic (photosynthesis)

Predators

White-tailed Deer
Eastern Cottontail
Pearl Crescent Caterpillar

ThreatsWetland drainage, invasive species encroachment like reed canary grass, and herbicide drift

HabitatsSwamps, fens, sedge meadows, wet prairies, stream banks, and roadside ditches

Life spanPerennial (indefinite via rhizomatous spread)

Classification

OrderAsterales
FamilyAsteraceae
GenusSymphyotrichum
SpeciesSymphyotrichum puniceum

Range & activity

Range data is not available yet.

Safe observation

Interaction riskLow

Low
Moderate
High
Very high

Why interaction risk is low: Safe to observe at a normal distance.

Responsible observation

Check the Stem: Run a finger gently along the lower stem to feel the stiff spreading hairs and see the purple coloration.
Look for Clasping Leaves: Identify the species by leaves that clasp the stem with flared, ear-like bases.
Late Autumn Viewing: Visit marshes in September and October when flowers are buzzing with native bees.

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