1. Leaves alternate..................................................................................................................................................................................2
2. Flowers unisexual...............................................................................................................................................................................3
3. Each fertile flower subtended by two modified sterile flowers...................................................... Digera muricata subsp. muricata
3. Fertile flower never subtended by modified sterile flowers............................................................................................. Amaranthus
2. Flowers hermaphrodite.......................................................................................................................................................................4
4. Fruit including one seed; stigma 1, capitate.......................................................................................................................................5
5. Annual herb; tepals 1.00− 1.25 mm long......................................................................................................... Nothosaerva brachiata
5. Perennial herb; tepals 3.25−4.00 mm long................................................................................................................... Saltia papposa
4. Fruit including 2 or more seeds; stigmas 2−3, linear.............................................................................................................. Celosia
1. Leaves opposite..................................................................................................................................................................................6
6. Synflorescence in axillary glomerules and/or terminal heads (no terminal spike- or panicle-structures).........................................7
7. Stigma 1, capitate.......................................................................................................................................................... Alternanthera
7. Stigmas 2, linear.................................................................................................................................................. Gomphrena globosa
6. Synflorescence in terminal spike- or panicle-structures and/or terminal heads.................................................................................8
8. Sterile flowers present......................................................................................................................... Pupalia lappacea var. velutina
8. Sterile flowers absent.........................................................................................................................................................................9
9. Synflorescence in terminal heads; pseudostaminoids absent................................................................ Psilotrichum gnaphalobryum
9. Synflorescence in terminal spike-structures; pseudostaminoids present..........................................................................................10
10. Stigmas 2, linear......................................................................................................................................................................... Aerva
10. Stigma 1, capitate.............................................................................................................................................................................11
11. Pseudostaminoids not fringed................................................................................................................ Psilotrichum gnaphalobryum
11. Pseudostaminoids fringed................................................................................................................................................. Achyranthes