| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| WIRE | Wislizenia refracta Engelm. | spectacle fruit | Capparaceae
|
| WISLI | Wislizenia Engelm. | wislizenia | Capparaceae
|
| WIAM | Wissadula amplissima (L.) R.E. Fries | big yellow velvetleaf | Malvaceae
|
| WICAF | Wissadula callimorpha (Hochr.) Hassler var. friesii Hassler | Pseudabutilon stuckertii | Malvaceae
|
| WICA5 | Wissadula callimorpha (Hochr.) Hassler | Pseudabutilon stuckertii | Malvaceae
|
| WIHO2 | Wissadula holosericea (Scheele) Garcke | Allowissadula holosericea | Malvaceae
|
| WIPE | Wissadula periplocifolia (L.) K. Presl ex Thwaites | white velvetleaf | Malvaceae
|
| WISSA | Wissadula Medik. | wissadula | Malvaceae
|
| WIFL | Wisteria floribunda (Willd.) DC. | Japanese wisteria | Fabaceae
|
| WIFO2 | Wisteria �formosa Rehd. | | Fabaceae
|
| WIFRM | Wisteria frutescens (L.) Poir. var. macrostachya Torr. & Gray | Wisteria frutescens | Fabaceae
|
| WIFR | Wisteria frutescens (L.) Poir. | American wisteria | Fabaceae
|
| WIMA | Wisteria macrostachya (Torr. & Gray) Nutt. ex B.L. Robins. & Fern. | Wisteria frutescens | Fabaceae
|
| WISI | Wisteria sinensis (Sims) DC. | Chinese wisteria | Fabaceae
|
| WISTE | Wisteria Nutt. | wisteria | Fabaceae
|
| WISO | Withania somnifera (L.) Dunal | withania | Solanaceae
|
| WITHA | Withania Pauquy | withania | Solanaceae
|
| WILI | Wittmackia lingulata (L.) Mez | Aechmea lingulata | Bromeliaceae
|
| WOAR2 | Wolffia arrhiza (L.) Horkel ex C.F.H. Wimmer | spotless watermeal | Lemnaceae
|
| WOBO | Wolffia borealis (Engelm. ex Hegelm.) Landolt ex Landolt & Wildi | northern watermeal | Lemnaceae
|
| WOBR | Wolffia brasiliensis Weddell | Brazilian watermeal | Lemnaceae
|
| WOCO | Wolffia columbiana Karst. | Columbian watermeal | Lemnaceae
|
| WOCY | Wolffia cylindracea Hegelm. | Wolffia globosa | Lemnaceae
|
| WOFL2 | Wolffia floridana (J.D. Sm.) J.D. Sm. ex Hegelm. | Wolffiella gladiata | Lemnaceae
|
| WOGLF | Wolffia gladiata Hegelm. var. floridana J.D. Sm. | Wolffiella gladiata | Lemnaceae
|
| WOGL4 | Wolffia gladiata Hegelm. | Wolffiella gladiata | Lemnaceae
|
| WOGL3 | Wolffia globosa (Roxb.) Hartog & Plas | Asian watermeal | Lemnaceae
|
| WOLI2 | Wolffia lingulata Hegelm. | Wolffiella lingulata | Lemnaceae
|
| WOPA | Wolffia papulifera C.H. Thompson | Wolffia brasiliensis | Lemnaceae
|
| WOPU2 | Wolffia punctata Griseb. | Wolffia brasiliensis | Lemnaceae
|
| WOPU | Wolffia punctata auct. non Griseb. | Wolffia borealis | Lemnaceae
|
| WOLFF | Wolffia Horkel ex Schleid. | watermeal | Lemnaceae
|
| WOFL | Wolffiella floridana (J.D. Sm.) C.H. Thompson | Wolffiella gladiata | Lemnaceae
|
| WOGL2 | Wolffiella gladiata (Hegelm.) Hegelm. | Florida mudmidget | Lemnaceae
|
| WOLI | Wolffiella lingulata (Hegelm.) Hegelm. | tongueshape bogmat | Lemnaceae
|
| WOOB | Wolffiella oblonga (Phil.) Hegelm. | saber bogmat | Lemnaceae
|
| WOLFF2 | Wolffiella Hegelm. | bogmat | Lemnaceae
|
| WOBI | Wollastonia biflora (l.) Dc. | | Asteraceae
|
| WOLLA | Wollastonia DC. ex Decaisne | | Asteraceae
|
| WOAB | Woodsia �abbeae Butters | | Dryopteridaceae
|
| WOALB2 | Woodsia alpina (Bolton) S.F. Gray var. bellii Lawson | Woodsia alpina | Dryopteridaceae
|
| WOAL | Woodsia alpina (Bolton) S.F. Gray | alpine woodsia | Dryopteridaceae
|
| WOAP | Woodsia appalachiana T.M.C. Taylor | Appalachian cliff fern | Dryopteridaceae
|
| WOCA | Woodsia cathcartiana B.L. Robins. | Woodsia oregana ssp. cathcartiana | Dryopteridaceae
|
| WOCO2 | Woodsia cochisensis Windham | Cochise cliff fern | Dryopteridaceae
|
| WOCO3 | Woodsia confusa T.M.C. Taylor | Woodsia abbeae | Dryopteridaceae
|
| WOGLB | Woodsia glabella R. Br. ex Richards. var. bellii (Lawson) Lawson | Woodsia alpina | Dryopteridaceae
|
| WOGL | Woodsia glabella R. Br. ex Richards. | smooth woodsia | Dryopteridaceae
|
| WOGR | Woodsia �gracilis (Lawson) Butters | | Dryopteridaceae
|
| WOILG | Woodsia ilvensis (L.) R. Br. var. gracilis Lawson | Woodsia gracilis | Dryopteridaceae
|
| WOIL | Woodsia ilvensis (L.) R. Br. | rusty woodsia | Dryopteridaceae
|
| WOKA | Woodsia �kansana R.E. Brooks | | Dryopteridaceae
|
| WONE | Woodsia neomexicana Windham | New Mexico cliff fern | Dryopteridaceae
|
| WOOBO | Woodsia obtusa (Spreng.) Torr. ssp. obtusa | bluntlobe cliff fern | Dryopteridaceae
|
| WOOBO2 | Woodsia obtusa (Spreng.) Torr. ssp. occidentalis Windham | western cliff fern | Dryopteridaceae
|
| WOOB2 | Woodsia obtusa (Spreng.) Torr. | bluntlobe cliff fern | Dryopteridaceae
|
| WOORC2 | Woodsia oregana D.C. Eat. ssp. cathcartiana (B.L. Robins.) Windham | Oregon cliff fern | Dryopteridaceae
|
| WOORO | Woodsia oregana D.C. Eat. ssp. oregana | Oregon cliff fern | Dryopteridaceae
|
| WOORC | Woodsia oregana D.C. Eat. var. cathcartiana (B.L. Robins.) Morton | Woodsia oregana ssp. cathcartiana | Dryopteridaceae
|
| WOORL | Woodsia oregana D.C. Eat. var. lyallii (Hook.) Boivin | Woodsia scopulina ssp. scopulina | Dryopteridaceae
|
| WOORS | Woodsia oregana D.C. Eat. var. squammosa Boivin | Woodsia abbeae | Dryopteridaceae
|
| WOOR | Woodsia oregana D.C. Eat. | Oregon cliff fern | Dryopteridaceae
|
| WOPH | Woodsia phillipsii Windham | Phillips' cliff fern | Dryopteridaceae
|
| WOPL | Woodsia plummerae Lemmon | Plummer's cliff fern | Dryopteridaceae
|
| WOSCA2 | Woodsia scopulina D.C. Eat. ssp. appalachiana (T.M.C. Taylor) Windham | Woodsia appalachiana | Dryopteridaceae
|
| WOSCL | Woodsia scopulina D.C. Eat. ssp. laurentiana Windham | Laurent's cliff fern | Dryopteridaceae
|
| WOSCS | Woodsia scopulina D.C. Eat. ssp. scopulina | Rocky Mountain woodsia | Dryopteridaceae
|
| WOSCA | Woodsia scopulina D.C. Eat. var. appalachiana (T.M.C. Taylor) Morton | Woodsia appalachiana | Dryopteridaceae
|
| WOSC | Woodsia scopulina D.C. Eat. | Rocky Mountain woodsia | Dryopteridaceae
|
| WOODS | Woodsia R. Br. | cliff fern | Dryopteridaceae
|
| WOAR | Woodwardia areolata (L.) T. Moore | netted chainfern | Blechnaceae
|
| WOCH | Woodwardia chamissoi Brack. | Woodwardia fimbriata | Blechnaceae
|
| WOFI | Woodwardia fimbriata Sm. | giant chainfern | Blechnaceae
|
| WORA | Woodwardia radicans (L.) J. Sm. | rooting chainfern | Blechnaceae
|
| WOVI | Woodwardia virginica (L.) Sm. | Virginia chainfern | Blechnaceae
|
| WOODW | Woodwardia Sm. | chainfern | Blechnaceae
|
| WONA | Wootonella nana (Gray) Standl. | Verbesina nana | Asteraceae
|
| WUBU | Wulfenia bullii (Eat.) Barnh. | Besseya bullii | Scrophulariaceae
|
| WUAP | Wullschlaegelia aphylla (Sw.) Reichenb. f. | leafless orchid | Orchidaceae
|
| WULLS | Wullschlaegelia Reichenb. f. | wullschlaegelia | Orchidaceae
|
| WYAM | Wyethia amplexicaulis (Nutt.) Nutt. | mule-ears | Asteraceae
|
| WYANF | Wyethia angustifolia (DC.) Nutt. var. foliosa (Congd.) Hall | Wyethia angustifolia | Asteraceae
|
| WYAN | Wyethia angustifolia (DC.) Nutt. | California compassplant | Asteraceae
|
| WYAR | Wyethia arizonica Gray | Arizona mule-ears | Asteraceae
|
| WYBO | Wyethia bolanderi (Gray) W.A. Weber | Bolander's mule-ears | Asteraceae
|
| WYCU | Wyethia �cusickii Piper (pro sp.) | | Asteraceae
|
| WYEL | Wyethia elata Hall | Hall's mule-ears | Asteraceae
|
| WYGL | Wyethia glabra Gray | Coast Range mule-ears | Asteraceae
|
| WYHE | Wyethia helenioides (DC.) Nutt. | whitehead mule-ears | Asteraceae
|
| WYHE2 | Wyethia helianthoides Nutt. | sunflower mule-ears | Asteraceae
|
| WYIN | Wyethia invenusta (Greene) W.A. Weber | Coville's mule-ears | Asteraceae
|
| WYLO | Wyethia longicaulis Gray | Humboldt mule-ears | Asteraceae
|
| WYMA | Wyethia �magna A. Nels. (pro sp.) | | Asteraceae
|
| WYMO | Wyethia mollis Gray | woolly mule-ears | Asteraceae
|
| WYOV | Wyethia ovata Torr. & Gray ex Torr. | southern mule-ears | Asteraceae
|
| WYRE | Wyethia reticulata Greene | El Dorado mule-ears | Asteraceae
|
| WYSCA | Wyethia scabra Hook. var. attenuata W.A. Weber | badlands mule-ears | Asteraceae
|
| WYSCC | Wyethia scabra Hook. var. canescens W.A. Weber | badlands mule-ears | Asteraceae
|
| WYSCS | Wyethia scabra Hook. var. scabra | badlands mule-ears | Asteraceae
|
| WYSC | Wyethia scabra Hook. | badlands mule-ears | Asteraceae
|
| WYETH | Wyethia Nutt. | mule-ears | Asteraceae
|