| 1. Hairs on lower surface leaf axes ± flat, segmented, ± 0.51 mm and nonsegmented, glandular, ± 0.1 mm |
| W. scopulina |
| 1' Hairs on lower surface leaf axes 0 or nonsegmented, glandular, ± 0.1 mm |
| |
| 2. Indusium of segmented hairs |
| W. oregana |
| 2' Indusium of scale-like fragments or lobes |
| W. plummerae
|