| 1 | Leaves retuse, panduriform or digitately lobed; perennial with trailing stems, growing on sandy seahores |
| 1' | Leaves acute, cordate or sagittate; annual with twining stems |
| 2 | Upper leaves narrowly sagittate with distinct lateral lobes; calyx-lobes obtuse, glabrous or subglabrous |
| 2' | Upper leaves broadly cordate; calyx-lobes acute, distinctly hairy |
