"…galls are 3–10 mm long; rounded, elliptical, or elongate-elliptical, depending on the width of the affected leaf; and black, usually with a narrow yellow, white, or purple margin…"

"[on E. caroliniana] ...the galls are found on the upper green stems in addition to the leaves… usually completely surround[ing] the stem, as in A. gutierreziae… Unlike for A. carbonifera, the epidermis does not peel off the galls in a layer 1 cell thick. Rather, the epidermis is incorporated with the fungi."

Asteromyia euthamiae is a multivoltine species that produces a leaf blister gall on Euthamia graminifolia (Linnaeus).

Black blister on leaf or stem. Galls are occasionally bordered with purple. Leaf galls may dehisce separately from the leaves. A euthamiae has several generations per year and presumably overwinters as full-grown larvae in the last generation of galls.