| 1. Perianth yellow or wine-red leaf fleshy; seashore |
| |
| 2. Leaf blade ± as long as wide; flower yellow |
| A. latifolia |
| 2' Leaf blade longer than wide; flower wine-red |
| A. maritima |
| 1' Perianth white, pink, or magenta |
| |
| 3. Stems densely tufted or in mats < 20 cm wide; montane perennial herb |
| |
| 4. Inflorescence 15 flowered; plant mat-forming; leaves cauline, blade ± round; fruit wing 0 |
| A. alpina |
| 4' Inflorescence many-flowered; plant densely tufted; leaves basal, blade oblong to ± round; fruit winged |
| A. nana subsp. covillei |
| 3' Stems elongate, aboveground; generally desert or seashore annual or perennial herb |
| |
| 5. Fruit wings 0; thick, prominent angles present or not; ovary chamber extends into angle |
| |
| 6. Perianth white to pale magenta; fruit angles generally 5, inflated and flat on top |
| A. turbinata |
| 6' Perianth generally bright pink; fruit smooth or with few low ridges |
| 2 A. villosa var. villosa |
| 5' Fruit with 25 thin, conspicuous wings; ovary chamber does not extend into wing |
| |
| 7. Fruit wings generally 2; fruit outline broadly cordate |
| A. pogonantha |
| 7' Fruit wings generally 35; fruit cordate, obconic, or ovoid |
| |
| 8. Leaves thin, widely scalloped; fruit beak inconspicuous, not hardened |
| A. gracilis |
| 8' Leaves thin or thick, ± entire; fruit beak evident, hardened |
| |
| 9. Fruit body ± smooth; immediate coast |
| A. umbellata |
| 10. Perianth light to dark magenta, inflorescence ± hemispheric; fruit wings broadly rounded |
| subsp. umbellata |
| 10' Perianth light magenta to ± yellow; inflorescence sparse; fruit wings angled near tip |
| subsp. breviflora |
| 9' Fruit body with prominent raised veins (most evident near tip); ± inland |
| A. villosa |
| 11. Fruit wings pronounced, exceeding top of fruit body; flower generally> 20 mm |
| var. aurita |
| 11' Fruit wings 0 or not exceeding top of fruit body; flower generally < 20 mm |
| var. villosa
|