Description: Perennial herbs with trailing or twining stems.
Leaves simple, entire, often sagittate or hastate, ± glabrous; hairs simple.
Flowers axillary, solitary or rarely in few-flowered cymes, with large persistent bracteoles ± enclosing the calyx. Sepals 5, free, subequal. Corolla campanulate to funnel-shaped, entire or shallowly 5-lobed, glabrous, with distinct mid-petaline bands. Stamens 5, subequal with short hairs along the basal fused margins of the filaments up to about the point of attachment. Ovary 1- or incompletely 2-locular with 4 ovules, glabrous; style 1, bearing 2 oblong or elliptic stigmatic lobes.
Capsule globose or ovoid, splitting longitudinally into 4 valves.
Distribution and occurrence: World: c. 25 species, mainly temperate regions. Australia: 4 species (3 species native, 1 species naturalized), all States except N.T.
Key modified by Peter G. Wilson, March 2021.
Text by R. W. Johnson
Taxon concept:
| | Key to the species | |
| 1 | Leaves somewhat fleshy, rounded, reniform; plants trailing, rarely weakly twining | Calystegia soldanella |
| Leaves membranous, ovate to sagittate, more or less acute; plants usually twining | 2 |
| 2 | Corolla less than 2.5 cm long | Calystegia marginata |
| Corolla more than 2.5 cm long
Back to 1 | 3 |
| 3 | Bracteoles acute | Calystegia sepium |
| Bracteoles obtuse to rounded or emarginate
Back to 2 | 4 |
| 4 | Corolla 2.5–3.5 cm long; bracteoles obtuse to rounded, to 1.5 cm long | Calystegia affinis |
| Corolla at least 4 cm long; bracteoles rounded to truncate, emarginate, 2–3.5 cm long
Back to 3 | Calystegia silvatica |
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