Annual to perennial herbs, rarely subshrubs. Leaves opposite or sometimes alternate, elliptic or lanceolate–deltate or ovate, margins entire to dentate with cordate to truncate or cuneate bases. Synflorescence cymose to subcymose, sometimes subumbellate. Phyllaries 30–40, distant, 2 or 3–seriate, equal or subequal, lanceolate, acute to acuminate, markedly hardened, often with scarious margins. Receptacle conical, glabrous or paleaceous. Florets 20–125. Corolla white, blue, or lavender, funnel form or with distinct basal tube; lobes 5, as long as wide, sparsely papillose and sometimes hispidulous on outer surface, papillose on inner surface; antheropodium cylindric; style base not enlarged, glabrous, style branches linear, usually strongly and densely papillose. Cypselas prismatic, 4–5–ribbed, glabrous or ribs setuliferous; carpopodium distinct. Pappus absent or of 5 or 6, free, flattened scales, sometimes awn–like.
A medium sized genus with ca 40 species, mostly native of South and Central America, few are naturalized in tropical and subtropical regions of the old world. Represented in Pakistan by two cultivated species of which A. conyzoides also grows as an escape.