| Ulex | Fabaceae |
| Ulmus | Ulmaceae |
| Urtica | Urticaceae |
| Utricularia | Lentibulariaceae |
| Uvularia | Liliaceae |
| Vaccaria | Caryophyllaceae |
| Vaccinium | Ericaceae |
| Vahlodea | Poaceae |
| Valeriana | Valerianaceae |
| Valerianella | Valerianaceae |
| Vallisneria | Hydrocharitaceae |
| Veratrum | Liliaceae |
| Verbascum | Scrophulariaceae |
| Verbena | Verbenaceae |
| Verbesina | Asteraceae |
| Vernonia | Asteraceae |
| Veronica | Scrophulariaceae |
| Veronicastrum | Scrophulariaceae |
| Viburnum | Caprifoliaceae |
| Vicia | Fabaceae |
| Vinca | Apocynaceae |
| Viola | Violaceae |
| Vitis | Vitaceae |
| Vulpia | Poaceae |
| Waldsteinia | Rosaceae |
| Weigela | Caprifoliaceae |
| Wisteria | Fabaceae |
| Wolffia | Lemnaceae |
| Wolffiella | Lemnaceae |
| Woodsia | Dryopteridaceae |
| Woodwardia | Blechnaceae |
| Xanthium | Asteraceae |
| Xanthorhiza | Ranunculaceae |
| Xyris | Xyridaceae |
| Yucca | Agavaceae |
| Zannichellia | Zannichelliaceae |
| Zanthoxylum | Rutaceae |
| Zea | Poaceae |
| Zigadenus | Liliaceae |
| Zinnia | Asteraceae |
| Zizania | Poaceae |
| Zizia | Apiaceae |
| Zostera | Zosteraceae |
Last Update: 1/6/97
Name: Ray Phillips
Email: rbphilli@Colby.edu