| 1 | Flowers 5-merous, leaves shiny, with evident venation |
| 1' | Flowers 3-4-merous, leaves dull, with inconspicuous to obscure venation |
| 2 | Anther a thin structure with 4 minute pollen sacs at its corners, completely fused with petal |
| 2' | Anther 2-lobed, incompletely fused with petal |
