Heads many-flowered. Receptacle chaffy 64
[*] 5. Pappus none, or a cup or crown, or of 2 or 3 awns, teeth, or chaffy scales corresponding with the edges or angles of the achene, often with intervening minute bristles or scales.
[+] Receptacle naked.
Achene flat, wing-margined. Pappus of separate little bristles and usually 2–4 awns 22
Achene flat, marginless. Pappus none. Receptacle conical 19
Achene terete or angled. Pappus none. Receptacle flattish 69
Achene angled. Pappus a little cup or crown (or none). Receptacle conical 20, 68
Achene fusiform. Pappus of few scales, usually with alternating awns 21
[+][+] Receptacle chaffy.
Rays neutral (rarely pistillate but sterile); the disk-flowers perfect and fertile.