pondweed

noun

1. Any of several plants that grow in ponds or similar aquatic conditions:

2. most commonlyPotamogeton, a diverse and worldwide genus

3. Elodea, found in North America

4. Azolla, of cosmopolitan distribution

5. Aponogeton, in Africa, Asia and Australasia

6. Opposite-leaved pondweed, Groenlandia densa, only plant of its genus, found chiefly in the Mediterranean region.

7. Charales, an order of green algae

8. Any of several submerged or floating freshwater perennial aquatic weeds belonging to the family Potamogetonaceaeplant