Much like no. 3 [Bacopa rotundifolia (Michx.) Wettst.]; stems glabrous, more often emersed; lvs 0.5-1 cm, fairly thick, obscurely 3-5-veined; pedicels 3-6 mm; upper sep broadly ovate-cordate, 4-6 mm; cor 3-5 mm, the lobes half as long as the tube; stamens 2-4. Wet places and shallow water; W.I. and C. Amer., n. to N.C., and in the intertidal zone to Va. and Md. (B. cyclophylla; B. stragula; Macuillamia obovata)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
