| Acer rubrum | Red Maple, Drummond's maple, Swamp Maple | 3 | 1 |
| Acer saccharinum | Silver Maple, River Maple, Soft Maple | 3 | 1 |
| Achillea millefolium | Yarrow, Boreal yarrow, California yarrow, Giant yarrow, Coast yarrow, Western yarrow, Pacific yarrow | 3 | 4 |
| Acorus gramineus | Grass-leaved Sweet Rush, Japanese Sweet Flag, Dwarf Sweet Flag | 3 | 3 |
| Actaea spicata | Herb Christopher, Baneberry | 0 | 1 |
| Aesculus glabra | Ohio Buckeye, Fetid Buckeye | 2 | 1 |