hydrilla
- n submersed plant with whorled lanceolate leaves and solitary axillary flowers; Old World plant naturalized in southern United States and clogging Florida's waterways
- Mullet swim through the dark tannin river water toward the clear spring water, which is lined with hydrilla, a fast-growing invasive weed.
- Two alien weeds, hydrilla and hyacinthborder officials don't know how they got thereare growing so fast they have blocked the flow of the river.
- Two alien weeds, hydrilla and hyacinth--border officials don't know how they got there--are growing so fast they have blocked the flow of the river.