Pycnanthemum tenuifolium Schrader
D.S. Correll, H.B. Correll, Aquatic Wetl. Pl. SW U.S.: , fig. 670 d,e (1972) [V. Frazier]
D.S. Correll, H.B. Correll, Aquatic Wetl. Pl. SW U.S.: , fig. 670 d,e (1972) [V. Frazier]