1	"Pistils, fruits +- fused at base; petals cut; flowers bisexual; stamens 6"	"Damasonium {Damasonium californicum}"
1	"Pistils, fruits free, in 1 whorl on margin of +- flat receptacle or spiralled on convex receptacle; petals +- cut to generally entire; flowers bisexual or unisexual; stamens 0, generally 6, or 7--30"	2
2	"Pistils, fruits in 1 whorl on margin of +- flat receptacle; stamens generally 6; flowers bisexual"	Alisma
2	"Pistils, fruits spiralled on convex receptacle; stamens 0 or 7--30; flowers bisexual or unisexual"	3
3	"Flowers bisexual; fruit cluster bur-like, beaks terminal, 0.6--1.3 mm"	"Echinodorus {Echinodorus berteroi}"
3	"Fls, or at least proximal, unisexual; fruit cluster not bur-like, beaks terminal, 0.1--0.4 mm, or lateral, 0.1--2 mm"	Sagittaria