1	"Plants with aerial, more or less succulent stems, sometimes arising from an enlarged base"	2
1	"Plants with subterranean tubers; leaves and inflorescences seeming to arise directly from the ground"	3
2	"Plants with a single stem or several stems more or less equally thick,with prominent leaf- and peduncle-scars; stipules usually persistent, conical"	"Dorstenia foetida"
2	"Plants with stems decreasing in size towards the growing points; leaf- and peduncle-scars soon disappearing because of the development of corky bark; stipules not persistent"	"Dorstenia gypsophila"
3	"Tubers depressed, disk-shaped, often more than 5 cm in diameter, often producing a short herbaceous stem which scarcely reaches above ground level; leaves ovate to elliptic,pinnately veined; receptacles circular"	"Dorstenia ellenbeckiana"
3	"Tubers taller than wide, up to 5 cm in diameter, sometimes with a distinct swelling on top but never producing a herbaceous stem; leaves as wide or wider than long, sometimes palmately divided, radiately or pedately veined; receptacles elliptic to linear"	"Dorstenia barnimiana"