| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Acetabularia crenulata | 0 | 0 | 1 |
| Achelous De Haan 1833 | 1 | 0 | 0 |
| Achelous ordwayi Stimpson 1860 | 0 | 0 | 1 |
| Acinetospora Bornet 1891 | 1 | 0 | 0 |
| Acinetospora crinita | 0 | 0 | 1 |
| Acinetosporaceae | 3 | 0 | 0 |
| Acmaea Eschscholtz 1833 | 1 | 0 | 0 |
| Eoacmaea pustulata (Helbling 1779) | 0 | 0 | 1 |
| Acmaeidae Forbes 1850 | 1 | 0 | 0 |
| Acrasiaceae | 1 | 0 | 0 |
| Acrasida | 1 | 0 | 0 |
| Acrasis | 1 | 0 | 0 |
| Acrasis rosea | 0 | 0 | 1 |
| Acrochaetiaceae | 1 | 0 | 0 |
| Acrochaetiales | 1 | 0 | 0 |
