| 1. Leaf simple, ± toothed; calyx lobes generally 2 (4 in some plants); fruit ± lanceolate in outline |
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| 2. Upper corolla lip hooded, not beaked; leaf crenate; stems generally simple |
| P. crenulata |
| 2' Upper corolla lip extended in a long, down-curved beak; leaf serrate to dentate; stems generally branched above |
| P. racemosa |
| 1' Leaf deeply lobed to compound; calyx lobes 5; fruit ovoid |
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| 3. Lower cauline leaf segments generally 35(7), ovate, entire to toothed, terminal largest; basal leaves 0 at flowering |
| P. howellii |
| 3' Lower cauline leaf segments > 5, serrate to divided, terminal segment not largest; basal leaves generally present at flowering (except P. bracteosa) |
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| 4. Corolla not club-like, upper lip with a long narrow, beak, lower lip ± fan-like |
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| 5. Corolla white to yellowish, upper lip 45.5 mm, beak curved downward, not very trunk-like |
| P. contorta |
| 5' Corolla pink to purple, upper lip 3.518 mm, beak curved upward, ± like an elephant's trunk |
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| 6. Inflorescence densely hairy; beak 35 mm; lower lip ± fan-like |
| P. attollens |
| 6' Inflorescence generally glabrous; beak 613 mm; outer lobes of lower lip appearing like ears |
| P. groenlandica |
| 4' Corolla ± club-like, upper lip hooded, not beaked; lower lip not fan-like |
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| 7. Corolla deep red to red-purple (or yellow to orange), lower lip ± 1/4 upper |
| P. densiflora |
| 7' Corolla yellowish or purplish, lower lip generally >> 1/4 upper |
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| 8. Stem 3090 cm; inflorescence > leaves; basal leaves generally 0 at flowering; corolla yellowish |
| P. bracteosa var. flavida |
| 8' Stem < 30 cm; inflorescence generally < or = leaves; basal leaves present at flowering; corolla yellowish or purplish |
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| 9. Corolla yellowish (sometimes purple-tipped), hairy; filaments hairy |
| P. semibarbata |
| 9' Corolla purplish, glabrous; filaments glabrous |
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| 10. Corolla 3042 mm, pale purple, darker-tipped, lower lip > 1/2 upper, its lobes rounded, wavy-margined; leaf margin wavy, white, thickened |
| P. centranthera |
| 10' Corolla 1724 mm, purple to purplish red, lower lip < upper, its lobes pointed, not wavy-margined; leaf margin not wavy, white, or thickened |
| P. dudleyi
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