| 1 | Woody climber. Tepals 10 or fewer. |
| 1' | Trees or shrubs. Tepals 13 or more. |
| 2 | Filaments relatively long and thin; mature anthers once or twice as long as the filaments. Seed smooth |
| 2' | Filaments relatively short and broad; mature anthers at least 4 times as long as the filaments. Seed with longitudinal or reticulate ridges |
