Parthenium hysterophorus	Ambrosia artemisiifolia	Artemisia vulgaris
top view of plant, stem glabrous	top view of plant, stem hairy	top view of plant, stem glabrous
heads not close together, flowers more obvious than involucre	inflorescence spike-like with many heads together, leafless, involucre more obvious than flowers	inflorescence spike-like with many heads together, leafy, involucre more obvious than flowers
leaves concolorous, pinnapartite	leaves concolorous, (double) pinnapartite	leaves discolorous, pinnapartite