Answer: What a good question. There are so many weeds, so many weeds. One of the most common weeds that we see in my area and the upper coastal region of South Carolina is a weed called slender spike rush. It’s a submersed weed. We see some shoreline vegetation weeds like primrose, alligator weed. There’s another weed, a floating weed, that we often see are fragrant water lilies, water shield. But getting back to the original question, the most dominant that I see is this submersed vegetation called slender spike rush.