Calystegia R.Br.
Perennial rhizomatous herbs with twining, creeping or rambling, usually glabrous stems. Latex present. Lvs petiolate, entire or basally lobed and often sagittate. Fls solitary, axillary, subtended by 2 large bracts partly or entirely concealing calyx. Sepals 5, subequal. Corolla of 5 shallow lobes, usually funnelform, sometimes campanulate, nearly always white or pink with white mid-petaline bands. Stamens 5, adnate to lower part of corolla tube, included. Ovary 1-locular or imperfectly 2-locular; ovules 4. Style included; stigma 2-lobed, included. Capsule 4-celled, ovoid to globose. Seeds usually smooth and glabrous.
Key
1
Stems prostrate or nearly so, not twining; lvs reniform, semi-succulent; corolla usually pink, occasionally whitish
Stems climbing, twining on host; lvs ovate to triangular, membranous; base cordate, sagittate or hastate; corolla white or pink
3
Lamina of lvs usually < 4 cm long; outer sepals broadly or elliptic-ovate; seeds orange
Bracts not or scarcely touching; corolla limb usually < 60 mm diam., usually pink with white mid-petaline bands, rarely completely white
c. 25 spp., widespread in temperate regions. Native spp. 3, naturalised 2.
