| 1 | Corolla white, tinged lilac, 5-6.5 mm long; annual with thin main root |
| 1' | Corolla with conspicuous bluish margins, often sharply contrasting, 5.5-12 mm long |
| 2 | Corolla 10-12 mm long; rhizomatous perennial; usually with at least some leaves longer than 4 cm |
| 2' | Corolla 5.5-9.5 mm long; annual with thin main root; leaves less than 1.5 cm long |
