| | 1. Corolla inconspicuous, ± included in bracts and calyces; stamens 2–4, upper 2 sterile and vestigial or 0, lower < 2 mm; (subg. Hedeomoides) |
| |
| | 2. Inflorescence a dense spike, from plant base to top; corolla white with purple spots |
| P. floribunda |
| | 2' Inflorescence dense, head-like, terminal and axillary clusters or flowers solitary in upper axils; corolla lavender to purple |
| |
| | 3. Plant inconspicuous; stem prostrate to decumbent, slender; fruit 1–1.3 mm; grassy areas |
| P. serpylloides |
| | 3' Plant conspicuous; stem ascending to erect, stout; fruit 1.5–2.5 mm; vernal pools, swales, drainages |
| P. zizyphoroides |
| | 1' Corolla conspicuous, exserted from bracts and calyces; stamens 4, fertile, lower > 3.5 mm (subg. Pogogyne) |
| |
| | 4. Inflorescence 1–3 cm wide; lower calyx lobes often 2 × upper; vernal pools, swales, n of Tehachapi Mountain Area |
| P. douglasii |
| | 4' Inflorescence < 2 cm wide; lower calyx lobes < 2 × upper; local endemics of coastal mesas, terraces (San Diego Co.), creekbeds (Monterey Co.) |
| |
| | 5. Calyx lobe tips flat; bract tips obtuse; corolla funnel-shaped; inflorescence < 10 mm wide |
| P. clareana |
| | 5' Calyx lobe tips not flat; bract tips acute or acuminate; corolla bell-shaped; inflorescence 8–20 mm wide |
| |
| | 6. Stem curved or zigzagged, thread-like, wiry-erect to lax-spreading; plant hairs dense, long, generally curved, coarse; inflorescence 8–10 mm wide |
| P. abramsii |
| | 6' Stem straight, stout, rigidly erect; plant hairs 0 or sparse, short, generally straight, bristle-like; inflorescence 10–20 mm wide |
| P. nudiuscula
|