Flowers floating or emersed, perianth spreading.

漂浮花者挺水，花被平展。

Anthers 6, opposite perianth segments, attached at lobe sinus, lobelet sinus, or lobe apex of corona, dorsifixed, introrse.

花药6，对生于花被，附着在缺，小缺，副花冠先，着，内向。

Achene straight, with crested or U-shaped appendix at apex or along dorsiventral edges, usually verrucose, invested by shorter persistent perianth.

瘦果直，有具脊者U形附属物在先者在腹边缘，通常多疣，被更窄宿存花被包围。

Epigyny The type of flower structure in which the perianth and androecium are inserted above the gynoecium, giving an inferior ovary, fused with the receptacle.

指花被和雄蕊群着生于雌蕊群之上花结构类型。