Gagné (1989) lists Symphyotrichum cordifolium (as Aster cordifolius) as the host for this stem-swelling gall, but Felt reported it from Doellingeria infirma (as Aster infirmus and earlier as Diplopappus cornifolius). I cannot find the rationale for this change. "cordifolius" ("heart-leaved") is only one letter away from "cornifolius" ("dogwood-leaved") - it's possible that it was misread.