Flowers floating or emersed, perianth spreading.

漂浮的者挺，平展。

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

药6，对生于片，附着裂片凹缺，小裂片凹缺，副冠裂片先端的，背着，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形附先端者背腹边缘，通常多疣，更窄的宿存包围。

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.

指和雄蕊群着生于雌蕊群之上的的结构类型。