| 1. Largest leaves entire or 3-lobed |
| P. bahiifolia |
| 1' Largest leaves 12-pinnately lobed |
| |
| 2. Largest leaves 1-pinnately lobed; phyllaries fused to 1/2 length |
| P. heermannii |
| 2' Largest leaves 2-pinnately lobed (except small plants); phyllaries fused only at base |
| P. peirsonii
|