Hydrocharitaceae

Limnobium spongia

Common Names: Spongeplant

Plant Form: Perennial mat-forming aquatic herb. Size: Up to 50 cm above surface of mud or water. Stem: Short stems branched with leaves, and longer leafless stems with daughter plants at ends. Leaves: Bright green shiny, thick, leathery, up to 10 cm long, oval or heart-shaped with pointed tip. Young leaves circular disk with spongey underside. Flowers: White, greenish-white or yellowish, 13 mm long. Fruit and Seeds: Fleshy berry-like capsules 4-18 mm long, with up to 200 tiny, bristled seeds. Habitat: Lakes, ponds, swamps, wetlands. Distinguishing Features: Larger fruit and pointed tipped leaves compared to Frogbit (Limnobium laevigatum). Impacts: Forms large mats affecting water flow and quality, reduces food and habitat for native aquatic species.