Aquatic Weed ID Guide

Watermeal
(Wolffia spp.)
Watermeal is the world’s smallest flowering plant, appearing as tiny, green granules that float on the water’s surface. It thrives in calm, nutrient-rich freshwater environments and often grows alongside duckweed, forming dense surface scums. Reproducing rapidly through vegetative budding, watermeal can double its population in as little as two days, leading to oxygen depletion and reduced sunlight penetration. While it serves as a food source for waterfowl, unmanaged watermeal can create an impenetrable layer that blocks sunlight and disrupts ecosystems. Effective control methods, including aeration and nutrient management, are essential for preventing its spread and maintaining a healthy pond.