Perennials, rhizomatous. Herb­age glabrate, glabrous, or hairy. Stems trailing or twining-climbing. Leaves: blade linear, ovate, broadly to narrowly tri­angular, or triangular-hastate, (24–)36–50(–150) mm, base usu­ally lobed, sometimes nearly truncate, lobes usually 1- or 2-pointed, sometimes rounded, basal sinus usu­ally acute to rounded, rarely almost closed. Bracts immediately subtending sepals, in subsp. erratica, intergrading with sepals, oblong, oval, or ovate, 12–34 × 5–26(–28) mm, proximally flat or keeled, not or scarcely saccate, margins not or scarcely enfolding sepals, apex acute to subobtuse or truncate. Flowers: sepals lanceolate, 10–19(–25) mm; corolla pink or white, (28–)30–70(–80) mm.

Distribution

North America, South America, Europe, Asia, Africa.

Discussion

Subspecies 8 (6 in the flora).

Subspecies of Calystegia sepium mostly show strong geographic separation; morphologic intermediates between subspecies of C. sepium and between C. sepium and other species of Calystegia make taxonomy difficult. Subspecies roseata Brummitt is known from Atlantic coasts of Europe, temperate coasts of South America, Easter Island, New Zealand, and Australia; subsp. spectabilis Brummitt is known from Europe and Asia.

Selected References

None.

Lower Taxa

Calystegia sepium subsp. americana, Calystegia sepium subsp. angulata, Calystegia sepium subsp. appalachiana, Calystegia sepium subsp. binghamiae, Calystegia sepium subsp. erratica, Calystegia sepium subsp. sepium

Key

1	Corollas white.	> 2
2	Leaf blade basal sinuses acute; corollas 30–50 mm; stamens 17–24 mm.	Calystegia sepium subsp. sepium
2	Leaf blade basal sinuses rounded; corollas (28–)44–65(–80) mm; stamens 19–32 mm.	> 3
3	Leaf blades broadly triangular, basal lobes spreading, ± 2-pointed.	Calystegia sepium subsp. angulata
3	Leaf blades linear to narrowly triangular, basal lobes slightly to abruptly spreading, 1-pointed or rounded.	Calystegia sepium subsp. binghamiae
1	Corollas pink.	> 4
4	Leaf blade basal sinuses almost closed; bracts intergrading with sepals.	Calystegia sepium subsp. erratica
4	Leaf blade sinuses acute or rounded; bracts not intergrading with sepals.	> 5
5	Herbage usually pubescent to tomentose, sometimes glabrate or glabrous; leaf blade sinuses acute.	Calystegia sepium subsp. americana
5	Herbage glabrous; leaf blade sinuses rounded.	Calystegia sepium subsp. appalachiana