1	"Herbs or woody subshrubs"	2
1	Vines	4
2	"Woody subshrubs"	Marsdenia
2	Herbs	3
3	"Corolla pink, white, yellow, brown, orange or red"	Asclepias
3	"Corolla blue or purple"	Oxypetalum
4	"Corolla lantern-shaped, usually with the lobes fused at tips"	Ceropegia
4	"Corolla not lantern-like, with lobes free at tips"	5
5	"Leaves fleshy to succulent, corolla bell-, wheel- or urn-shaped"	6
5	"Leaves herbaceous, corolla salver-shaped"	7
6	"Corolla urn-shaped"	Dischidia
6	"Corolla wheel- or bell-shaped"	Hoya
7	"Leaves mealy-waxy, matt; corolla tube less than 2 cm long"	Araujia
7	"Leaves smooth, glossy; corolla tube greater than 2 cm long"	Marsdenia