Key for Sagittaria L.

1Pedicels in fruit spreading, not thickened, 0.3-0.4 mm wide; sepals reflexed or spreading from fruiting aggregate
1'Pedicels in fruit reflexed or spreading, thickened, 1.2-5.5 mm wide; sepals appressed or erect around fruiting aggregate
2Leaves and inflorescences submersed or floating; floating leaves with cordate, sagittate, or hastate base, basal lobes present
2'Leaves and inflorescences emerged or submersed, not floating; emerged leaves with acute to subcordate base, basal lobes absent