Symphyotrichum puniceum - Swamp Aster
This is a glossy-leaf aster that typically occurs in swampy ground. An erect, tall growing plant which grows to a height of 4-8'. It has small but abundant flowers, 1 1/2 inches across with light violet blue to purple rays and yellow center discs which bloom in autumn. It is late blooming and still looks fresh at time of first frost. Good for a back border in a garden, and attracts butterflies.
Full Sun, Medium to Wet Soil, Fall, 6'-8' Tall, Zones 2-9