Justicia americana (L.) Vahl
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Colonial by rhizomes; stems 5–10 dm, often rooting below, usually simple, glabrous; lvs linear to lanceolate or narrowly oblong, 8–16 cm × 8–25 mm, long-cuneate at base; peduncles from several upper axils, stiffly ascending, 5–15 cm; spikes 1–3 cm, crowded with opposite fls, the cal longer than the internode above it; cal-lobes narrowly lanceolate, 4–8 mm; cor 8–13 mm, the lobes about equaling or a little longer than the tube, pale violet to nearly white, marked with purple on the lower lip; terminal pollen-sac transverse; seeds densely verrucose, 3 mm wide; 2n=26. Mud and shallow water; w. Que. to Mich. and Wis., s. and sw. to Ga., Kans., and Tex. June–Aug. (J. mortuifluminis; Dianthera a.)