WILLOW LEAF ASTER
ASTER PRAEALTUS   ASTERACEAE (SUNFLOWER)

ALSO CALLED: Symphyotrichum praealtum, WILLOW ASTER, AND TALL ASTER 

TALLGRASS PRAIRIE WILDFLOWERS  P. 75

http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=ASTPRA

http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=SYPRP