18c. Calystegia sepium (Linnaeus) R. Brown subsp. binghamiae (Greene) Brummitt, Ann. Missouri Bot. Gard. 52: 216. 1965.
[W]
Convolvulus binghamiae Greene, Bull. Calif. Acad. Sci. 2: 417. 1887; Calystegia sepium subsp. limnophila (Greene) Brummitt; Convolvulus nashii House
Herbage usually pubescent to tomentose, sometimes glabrate or glabrous. Leaf blades linear to narrowly triangular, basal lobes slightly to abruptly spreading, 1-pointed or rounded, basal sinus narrowly rounded. Bracts 14–24 × 10–16 mm, proximally flat or keeled. Flowers: corolla white, limb margin rarely pink-tinged, (30–)44–65 mm; stamens 26–32 mm.
Flowering mostly Mar–Jul. Marshes, stream banks; Calif., Fla., Ga., La., Nev., N.Mex., N.C., S.C., Tex.; Mexico (Baja California); South America (Peru).
When M. C. Provance and A. C. Sanders named Calystegia felix, they noted that Brummitt had long included specimens of C. felix within his circumscription of C. sepium subsp. binghamiae and that the names C. sepium subsp. binghamiae Brummitt and C. sepium subsp. limnophylla (Greene) Brummitt belong to a single subspecies circumscription. They chose to call that subspecies C. sepium subsp. binghamiae (Greene) Brummitt.
