Flowers floating or emersed, perianth spreading.

漂挺水，被平展。

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

药6，对生于被片，附着裂片凹缺，小裂片凹缺，副冠裂片先端，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U形附属物先端腹边缘，通常多疣，被更窄宿存被包围。

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.

指被和雄蕊群着生于雌蕊群之上结构类型。