blooming water plantain

This summer, scant rain fell in July and August. The pond suffered lower water levels as each day passed.  

Eventually, some aquatic plants that grow at the edge of the pond stood in mud rather than in shallow water. 

But the Northern Water Plantain Alisma triviale thrived despite the drought.  It sent up stems more than 2 feet high on which many whorls of white flowers opened, each about 1/4" across.