| 1 | Sepals more than 2 times as long as wide; leaves often densely pubescent beneath |
| 1' | Sepals less than 2 times as long as wide; leaves glabrous or puberulent only on midrib beneath |
| 2 | Leaves densely dark pubescent beneath; ovary pubescent; fruit pear-shaped with a long narrow neck |
| 2' | Leaves sparsely to densely pale pubescent beneath; ovary glabrous; fruit ovoid to slightly pear-shaped with a very short neck |
| 3 | Corolla tube densely pubescent at base inside; secondary veins 2-5 pairs |
| 3' | Corolla tube glabrous at base inside; secondary veins 5-10 pairs |
