Genus of aquatic herbs of temperate and tropical regions having sagittate or hastate leaves and white scapose flowers .

生长于温带或热带地区的一个水生草本植物属，叶箭头状或戟形，花具花葶，白色花。

Inflorescence terminal or lateral , scapose or sessile , a panicle , raceme , spike , or head , sometimes reduced to solitary , pseudolateral flowers ; bracts usually brightly colored and conspicuous .

花序顶生或者侧生，具花葶或者无柄，圆锥花序，总状花序，穗状花序或者头状花序，有时仅有假侧生的单生花；苞片通常颜色鲜艳，显著。