Cattail appear in the upper-right picture.
Emergent weeds (or emersed weeds) are often rooted along shorelines with stems or other biomass extending above the water surface (cattails are a good example). Because of this, their stems are often somewhat stiff or firm.
Cattails have dense, "sausage-like," spikey flowers called catkins that appear on top of the long, slender stems in late summer to early fall. Cattails can be partially submerged or in boggy areas with no permanently standing water and can grow to 5 or 10 feet in height. They provide a wildlife habitat and refuge. Overgrowth can choke off open water, driving away birds.
Bulrush (Scirpus spp.)
Bulrush grow in shallow water and moist soils, with shorelines of ponds providing a great habitat for these plants. Some may reach 8 - 10 feet in height. Some bulrush species have three sided stems like sedge, and leaves that grow on the lower stems. Irregular seed clusters are densely packed near stem tips.
Sedges (Cyperaceae spp.)
Sedges thrive in wet places and have triangular (3-sided) stems. There are about 2000 species of grass-like perennial herbs in the sedge grass family. Found worldwide, they are most common in temperate and cold regions. Sedges can be distinguished from grasses by their solid, 3-angled flower stems (grasses have round, hollow flower stems). Most species of sedges form a dense, compact clump.
Types & Solutions
by West Bishop (video)