Symphyotrichum anticostense (formerly Aster anticostensis) is a species of flowering plant in the family Asteraceae with the common name of Anticosti aster. It is endemic to Quebec, New Brunswick, and Maine. S. anticostense is a perennial, herbaceous plant that may reach 10to in height. Its flowers have pale purple or lilac, sometimes white, ray florets and yellow, then reddish purple, disk florets.
Symphyotrichum anticostense is a perennial, herbaceous plant that may reach 10to in height. It grows in clonal colonies from long rhizomes, each which produces one erect, red-toned, and hairless stem. Its flower heads are found in long and somewhat racemiform arrays. The involucre of each flower head is bell-shaped and NaNabbr=offNaNabbr=off long. Its flowers have 25–44 pale purple or lilac, sometimes white, ray florets, size NaNmm long by NaNmm wide. The ray florets surround 29–52 yellow, maturing to reddish-purple, disk florets.
Symphyotrichum anticostense is classified in the subgenus Symphyotrichum, section Symphyotrichum, subsection Symphyotrichum. The species' common name is "Anticosti aster".
Symphyotrichum anticostense is endemic to Quebec, New Brunswick, and Maine. It is a river and lake gravel shore plant that is conditioned to these calcareous habitats.
Symphyotrichum anticostense is vulnerable for reasons including erosion, deer browsing, and invasive species encroachment. In Maine, it is critically endangered.