| 1 | Corolla throat glabrous or with only 5 small patches of hair |
| 1' | Corolla throat continuously and densely pubescent |
| 2 | Stamens inserted at top of corolla tube with anthers slightly exserted; corolla throat glabrous or with the tops of the 5 patches of hairs behind the stamens just visible. |
| 2' | Stamens inserted in lower half or around middle of corolla tube, anthers not exserted from corolla tube; corolla throat glabrous |
