Both aquatic flora and Mississippi flora are underrepresented in herbarium collections. This paper reports nine noteworthy collections of 6 aquatic and wetland taxa in Alabama, Arkansas, and Mississippi. These taxa include 5 angiosperms and 1 charophyte. Two of these taxa are introduced to the United States, while the rest are presumed native. Lychnothamnus barbatus, Utricularia tenuicaulis, and Vallisneria ×pseudorosulata are new to the flora of Mississippi and Cyperus blepharoleptos is new to the flora of Arkansas.