Receptacle mostly elevated (varying from convex to columnar), and
Chaffy only at the summit; the chaff deciduous. Pappus none 66
Chaffy throughout. Achene flattened laterally if at all 48, 49, 50, 52, 54
Receptacle flat or flattish. Achene flattened, parallel with the scales or chaff 55, 56
Receptacle flat. Achene terete, 2-awned 57
Rays pistillate and fertile; the disk-flowers also perfect and fertile.
Achene much flattened laterally, 1–2-awned 53
Achene flattened parallel with the scales and chaff. Pappus none 67
Achene 3–4-angular, terete or laterally flattish, awnless.
Receptacle convex or conical. Leaves alternate, dissected 66