1	"Stigma linear, included; inflorescence a head or umbel; fruit generally winged"	2
1	"Stigma +- spheric, generally exserted; inflorescence a head or umbel or not; fruit generally unwinged"	3
2	"Fruit wings thick or 0, not surrounding fruit body; flowers maturing outer before inner or +- simultaneously; receptacle conic, +- smooth"	Abronia
2	"Fruit wings translucent, surrounding fruit body; flowers maturing 1 side of inflorescence before the other; receptacle flat or rounded, studded with peg-shaped pedicel-like projections"	Tripterocalyx
3	"Bracts 3 or 5(9), generally at least partially fused, forming a calyx-like involucre"	4
3	"Bracts 1--3, free, not forming an involucre"	5
4	"Flowers strongly bilateral, in 1 involucre 3, blooming +- together; bracts 3; fruit bilateral"	Allionia
4	"Flowers radial or +- bilateral, in 1 involucre 1--16, generally not blooming together; bracts 5(9); fruit radial"	Mirabilis
5	"Stem erect, > 7 mm diam; fruit glabrous, with 10 inconspicuous ribs"	"Anulocaulis {Anulocaulis annulatus}"
5	"Stem decumbent to erect, generally << 5 mm diam; fruit hairy or not, with (4)5 prominent ribs or wings"	6
6	"Perianth tube 30--170 mm, trumpet-shaped; fruit oblong, glabrous, 5--10 mm"	Acleisanthes
6	"Perianth tube < 5 mm, bell-shaped; fruit club-shaped, glabrous or hairy, < 4 mm"	Boerhavia