| Name | Children | Media (from resource) | Traits |
|---|---|---|---|
| Welwitschiaceae (Welwitschia) | 1 | 0 | 0 |
| West Nile virus | 0 | 2 | 0 |
| Wisteria sinensis (Sims) Sweet (Chinese wisteria) | 0 | 2 | 0 |
| Wisterion | 1 | 2 | 0 |
| Wolbachia | 0 | 2 | 0 |
| Woodsiaceae (Lady ferns and brittle ferns) | 0 | 2 | 0 |
| Woodwardia (chainfern) | 1 | 0 | 0 |
| Woodwardia radicans (L.) Sm. (rooting chainfern) | 0 | 2 | 0 |
| Woodwardioideae | 1 | 0 | 0 |
| Xanthocyparis | 0 | 2 | 0 |
| Xanthomonadaceae | 2 | 0 | 0 |
| Xanthomonadales | 1 | 0 | 0 |
| Xanthomonas | 1 | 2 | 0 |
| Xanthomonas campestris (Citrus canker) | 0 | 2 | 0 |
| Xanthophyceae (yellow-green algae) | 0 | 2 | 0 |
