1	"Leaves more or less fleshy, reniform, apex rounded or emarginate; bracteoles slightly shorter than calyx; stems trailing, rarely twining (coastal habitats)"	"Calystegia soldanella"
1	"Leaves membranous, ovate to lanceolate, apex acute; bracteoles longer than the calyx; stems twining (not always coastal)"	2
2	"Corolla < 2.5 cm long; bracteoles more or less orbicular, usually < 1 cm long; peduncles shorter than petioles"	"Calystegia marginata"
2	"Corolla > 2.5 cm long; bracteoles more or less ovate, less than or equal to 1 cm long; peduncles longer than petioles"	3
3	"Bracteoles 1.5-2 cm long, < 15 mm wide, not overlapping, apex acute, base flat or keeled; capsule subglobose, 7-8 mm long"	"Calystegia sepium"
3	"Bracteoles 2-3.5 cm long, > 15 mm wide, overlapping, apex blunt, base conspicuously inflated, more or less cordate and keeled; capsule ovoid, 10-12 mm long"	"Calystegia silvatica"