Ambrosia L.


4 species naturalized Aust.; NSW, Vic., S.A., WA

Monoecious, annual or perennial herbs, frequently becoming woody towards the base. Leaves opposite or alternate, Male heads numerous, in terminal racemes, each several–many-flowered; receptacle with scales between the florets; corolla 5-toothed; stamens 5. Female heads solitary or few together in the leaf axils below the male heads, 1-flowered; Florets without corollas, surrounded by several connate bracts; style 2-fid, protruding beyond the involucre. Pappus absent. Cypsela surrounded by the persistent involucre.