| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| XANE2 | Xanthoparmelia neoconspersa (Gyelnik) Hale | | Parmeliaceae
|
| XANE3 | Xanthoparmelia neotaractica Hale | | Parmeliaceae
|
| XANE4 | Xanthoparmelia neowyomingica Hale | | Parmeliaceae
|
| XANI2 | Xanthoparmelia nigropsomifera (T. Nash) Egan | | Parmeliaceae
|
| XANO | Xanthoparmelia norchlorochroa Hale | | Parmeliaceae
|
| XANO2 | Xanthoparmelia norhypopsila Hale | | Parmeliaceae
|
| XANO3 | Xanthoparmelia novomexicana (Gyelnik) Hale | | Parmeliaceae
|
| XAOL2 | Xanthoparmelia oleosa (Elix & P. M. Armstrong) Elix & T. Nash | | Parmeliaceae
|
| XAPI2 | Xanthoparmelia piedmontensis (Hale) Hale | | Parmeliaceae
|
| XAPL | Xanthoparmelia planilobata (Gyelnik) Hale | | Parmeliaceae
|
| XAPL2 | Xanthoparmelia plittii (Gyelnik) Hale | | Parmeliaceae
|
| XAPS | Xanthoparmelia psoromifera (Kurok.) Hale | | Parmeliaceae
|
| XASC | Xanthoparmelia schmidtii Hale | | Parmeliaceae
|
| XASE | Xanthoparmelia separata (Th. Fr.) Hale | Arctoparmelia separata | Parmeliaceae
|
| XASO2 | Xanthoparmelia somloensis (Gyelnik) Hale | | Parmeliaceae
|
| XAST3 | Xanthoparmelia stenophylloides (Mull. Arg.) Hale | | Parmeliaceae
|
| XASU6 | Xanthoparmelia subcentrifuga (Oksner) Hale | Arctoparmelia subcentrifuga | Parmeliaceae
|
| XASU7 | Xanthoparmelia subconspersa (Nyl.) Hale | Flavoparmelia rutidota | Parmeliaceae
|
| XASU2 | Xanthoparmelia subdecipiens (Vainio) Hale | | Parmeliaceae
|
| XASU3 | Xanthoparmelia subramigera (Gyelnik) Hale | | Parmeliaceae
|
| XASU4 | Xanthoparmelia substenophylloides Hale | | Parmeliaceae
|
| XATA60 | Xanthoparmelia taractica (Krempelh.) Hale | Xanthoparmelia somloensis | Parmeliaceae
|
| XATA2 | Xanthoparmelia tasmanica (Hook. f. & Taylor) Hale | | Parmeliaceae
|
| XATU | Xanthoparmelia tucsonensis (T. Nash) Egan | | Parmeliaceae
|
| XAVA2 | Xanthoparmelia vagans (Nyl.) Hale | | Parmeliaceae
|
| XAWE | Xanthoparmelia weberi (Hale) Hale | | Parmeliaceae
|
| XAWY | Xanthoparmelia wyomingica (Gyelnik) Hale | | Parmeliaceae
|
| XANTH7 | Xanthoparmelia (Vainio) Hale | xanthoparmelia | Parmeliaceae
|
| XATE6 | Xanthopsora texana (W. A. Weber) Gotth. Schneider & W. A. Weber | Xanthopsorella texana | Catillariaceae
|
| XATE5 | Xanthopsorella texana (W. A. Weber) Kalb & Hafellner | | Catillariaceae
|
| XANTH8 | Xanthopsorella Kalb & Hefellner | xanthopsorella | Catillariaceae
|
| XASI | Xanthorhiza simplicissima Marsh. | yellowroot | Ranunculaceae
|
| XANTH5 | Xanthorhiza Marsh. | yellowroot | Ranunculaceae
|
| XAAL2 | Xanthoria alaskana J. W. Thomson | orange wall lichen | Teloschistaceae
|
| XAAL3 | Xanthoria alfredi S. Kondratyuk & Poelt | orange wall lichen | Teloschistaceae
|
| XABO | Xanthoria borealis R. Sant. & Poelt | orange wall lichen | Teloschistaceae
|
| XACAF | Xanthoria candelaria (L.) Th. Fr. var. finmarkica (Ach.) Hillm. | orange wall lichen | Teloschistaceae
|
| XACA60 | Xanthoria candelaria (L.) Th. Fr. | orange wall lichen | Teloschistaceae
|
| XACO7 | Xanthoria concinna J. W. Thomson & T. Nash | orange wall lichen | Teloschistaceae
|
| XAELS | Xanthoria elegans (Link) Th. Fr. var. splendens (Darbish.) M. S. Christ. ex Poelt | elegant orange wall lichen | Teloschistaceae
|
| XAEL60 | Xanthoria elegans (Link) Th. Fr. | elegant orange wall lichen | Teloschistaceae
|
| XAFAF | Xanthoria fallax (Hepp) Arnold var. fallax | orange wall lichen | Teloschistaceae
|
| XAFA | Xanthoria fallax (Hepp) Arnold | orange wall lichen | Teloschistaceae
|
| XAFU | Xanthoria fulva (Hoffm.) Poelt & Petutschnig | orange wall lichen | Teloschistaceae
|
| XAHA | Xanthoria hasseana Rasanen | Hasse's orange wall lichen | Teloschistaceae
|
| XALO | Xanthoria lobulata (Florke) de Lesd. | Caloplaca lobulata | Teloschistaceae
|
| XAOR2 | Xanthoria oregana Gyelnik | Xanthoria candelaria | Teloschistaceae
|
| XAPA | Xanthoria papillifera (Vainio) Poelt | orange wall lichen | Teloschistaceae
|
| XAPA2 | Xanthoria parietina (L.) Th. Fr. | orange wall lichen | Teloschistaceae
|
| XAPO60 | Xanthoria polycarpa (Hoffm.) Rieber | orange wall lichen | Teloschistaceae
|
| XARA | Xanthoria ramulosa (Tuck.) Herre | orange wall lichen | Teloschistaceae
|
| XASO60 | Xanthoria sorediata (Vainio) Poelt | orange wall lichen | Teloschistaceae
|
| XASU5 | Xanthoria subramulosa Rasanen | orange wall lichen | Teloschistaceae
|
| XAUL | Xanthoria ulophyllodes Rasanen | orange wall lichen | Teloschistaceae
|
| XANTH9 | Xanthoria (Fr.) Th. Fr. | orange wall lichen | Teloschistaceae
|
| XAAT | Xanthosoma atrovirens K. Koch & Bouch� | yautia amarilla | Araceae
|
| XABR | Xanthosoma brasiliense (Desf.) Engl. | Tahitian spinach | Araceae
|
| XACA | Xanthosoma caracu K. Koch & Bouch� | yautia horqueta | Araceae
|
| XAHE | Xanthosoma helleborifolium (Jacq.) Schott | belembe silvestre | Araceae
|
| XAJA | Xanthosoma jacquinii Schott | Xanthosoma undipes | Araceae
|
| XANI | Xanthosoma nigrum (Vell.) Stellfeld | Xanthosoma violaceum | Araceae
|
| XARO | Xanthosoma robustum Schott | capote | Araceae
|
| XARO2 | Xanthosoma roseum Schott | rosy malanga | Araceae
|
| XASA2 | Xanthosoma sagittifolium (L.) Schott | arrowleaf elephant's ear | Araceae
|
| XAUN | Xanthosoma undipes (K. Koch) K. Koch | tall elephant's ear | Araceae
|
| XAVI | Xanthosoma violaceum Schott | purplestem taro | Araceae
|
| XANTH4 | Xanthosoma Schott | elephant's ear | Araceae
|
| XAAL | Xanthoxalis albicans (Kunth) Small | Oxalis albicans ssp. albicans | Oxalidaceae
|
| XABR2 | Xanthoxalis brittoniae (Small) Small | Oxalis stricta | Oxalidaceae
|
| XABU | Xanthoxalis bushii Small | Oxalis stricta | Oxalidaceae
|
| XACO4 | Xanthoxalis coloradensis (Rydb.) Rydb. | Oxalis stricta | Oxalidaceae
|
| XACO3 | Xanthoxalis colorea Small | Oxalis priceae ssp. colorea | Oxalidaceae
|
| XACOA | Xanthoxalis corniculata (L.) Small var. atropurpurea (Planch.) Moldenke | Oxalis corniculata | Oxalidaceae
|
| XACO2 | Xanthoxalis corniculata (L.) Small | Oxalis corniculata | Oxalidaceae
|
| XACY2 | Xanthoxalis cymosa (Small) Small | Oxalis stricta | Oxalidaceae
|
| XADIP | Xanthoxalis dillenii (Jacq.) Holub var. piletocarpa (Wieg.) Holub | Oxalis stricta | Oxalidaceae
|
| XADI | Xanthoxalis dillenii (Jacq.) Holub | Oxalis stricta | Oxalidaceae
|
| XAFI | Xanthoxalis filipes (Small) Small | Oxalis stricta | Oxalidaceae
|
| XAFL | Xanthoxalis florida (Salisb.) Moldenke | Oxalis stricta | Oxalidaceae
|
| XAGR | Xanthoxalis grandis (Small) Small | Oxalis grandis | Oxalidaceae
|
| XAHI | Xanthoxalis hirsuticaulis (Small) Small | Oxalis priceae ssp. priceae | Oxalidaceae
|
| XAIN2 | Xanthoxalis interior Small | Oxalis stricta | Oxalidaceae
|
| XALA | Xanthoxalis langloisii Small | Oxalis corniculata | Oxalidaceae
|
| XALY | Xanthoxalis lyonii (Pursh) Holub | Oxalis priceae ssp. texana | Oxalidaceae
|
| XAMA2 | Xanthoxalis macrantha auct. non (Trel.) Small | Oxalis suksdorfii | Oxalidaceae
|
| XAPI | Xanthoxalis pilosa (Nutt.) Small | Oxalis albicans ssp. pilosa | Oxalidaceae
|
| XAPR | Xanthoxalis priceae (Small) Small | Oxalis priceae ssp. priceae | Oxalidaceae
|
| XARE2 | Xanthoxalis recurva (Ell.) Small | Oxalis priceae ssp. colorea | Oxalidaceae
|
| XARE | Xanthoxalis repens (Thunb.) Moldenke | Oxalis corniculata | Oxalidaceae
|
| XARU | Xanthoxalis rufa (Small) Small | Oxalis stricta | Oxalidaceae
|
| XASTP2 | Xanthoxalis stricta (L.) Small var. piletocarpa (Wieg.) Moldenke | Oxalis stricta | Oxalidaceae
|
| XAST2 | Xanthoxalis stricta (L.) Small | Oxalis stricta | Oxalidaceae
|
| XASU | Xanthoxalis suksdorfii (Trel.) Small | Oxalis suksdorfii | Oxalidaceae
|
| XATE3 | Xanthoxalis texana Small | Oxalis priceae ssp. texana | Oxalidaceae
|
| XAWR2 | Xanthoxalis wrightii (Gray) Abrams | Oxalis albicans ssp. albicans | Oxalidaceae
|
| XEUM | Xeniatrum umbellulatum (Michx.) Small | Clintonia umbellulata | Liliaceae
|
| XETR | Xenostegia tridentata (L.) Austin & Staples | African morningvine | Convolvulaceae
|
| XENOS | Xenostegia Austin & Staples | morningvine | Convolvulaceae
|
| XEBR | Xeranthemum bracteatum Vent. | Helichrysum bracteatum | Asteraceae
|
| XEAS | Xerophyllum asphodeloides (L.) Nutt. | eastern turkeybeard | Liliaceae
|
| XETE | Xerophyllum tenax (Pursh) Nutt. | common beargrass | Liliaceae
|