| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| QUSU3 | Quercus ×substellata Trel. | | Fagaceae
|
| QUSU10 | Quercus succulenta Small | Quercus laurifolia | Fagaceae
|
| QUTA | Quercus tardifolia C.H. Muller | lateleaf oak | Fagaceae
|
| QUTE | Quercus texana Buckl. | Texas red oak | Fagaceae
|
| QUTE2 | Quercus texana auct. non Buckl. | Quercus buckleyi | Fagaceae
|
| QUTH | Quercus ×tharpii C.H. Muller (pro sp.) | | Fagaceae
|
| QUTO | Quercus tomentella Engelm. | island live oak | Fagaceae
|
| QUTO4 | Quercus ×tottenii Melvin | | Fagaceae
|
| QUTO2 | Quercus toumeyi Sarg. | Toumey oak | Fagaceae
|
| QUTO3 | Quercus ×townei Palmer | | Fagaceae
|
| QUTR | Quercus ×tridentata (A. DC.) Trel. (pro sp.) | | Fagaceae
|
| QUTR3 | Quercus triloba Michx. | Quercus falcata | Fagaceae
|
| QUTUA2 | Quercus turbinella Greene ssp. ajoensis (C.H. Muller) Felger & Lowe | Quercus ajoensis | Fagaceae
|
| QUTUC | Quercus turbinella Greene ssp. californica Tucker | Quercus john-tuckeri | Fagaceae
|
| QUTUA | Quercus turbinella Greene var. ajoensis (C.H. Muller) Little | Quercus ajoensis | Fagaceae
|
| QUTUC2 | Quercus turbinella Greene var. californica (Tucker) L. Benson | Quercus john-tuckeri | Fagaceae
|
| QUTU2 | Quercus turbinella Greene | Sonoran scrub oak | Fagaceae
|
| QUUN | Quercus undulata Torr. | Quercus pauciloba | Fagaceae
|
| QUUT | Quercus utahensis (A. DC.) Rydb. | Quercus gambelii var. gambelii | Fagaceae
|
| QUVA | Quercus vacciniifolia Kellogg | huckleberry oak | Fagaceae
|
| QUVA2 | Quercus ×vaga Palmer & Steyermark | | Fagaceae
|
| QUVA5 | Quercus vaseyana Buckl. | sandpaper oak | Fagaceae
|
| QUVEM | Quercus velutina Lam. var. missouriensis Sarg. | Quercus velutina | Fagaceae
|
| QUVE | Quercus velutina Lam. | black oak | Fagaceae
|
| QUVE2 | Quercus ×venulosa Ashe | | Fagaceae
|
| QUVE3 | Quercus venustula Greene | Quercus pauciloba | Fagaceae
|
| QUVI2 | Quercus viminea Trel. | | Fagaceae
|
| QUVIF | Quercus virginiana P. Mill. var. fusiformis (Small) Sarg. | Quercus fusiformis | Fagaceae
|
| QUVIG | Quercus virginiana P. Mill. var. geminata (Small) Sarg. | Quercus geminata | Fagaceae
|
| QUVIM3 | Quercus virginiana P. Mill. var. maritima (Michx.) Sarg. | Quercus geminata | Fagaceae
|
| QUVIM2 | Quercus virginiana P. Mill. var. minima Sarg. | Quercus minima | Fagaceae
|
| QUVI | Quercus virginiana P. Mill. | live oak | Fagaceae
|
| QUVR | Quercus vreelandii Rydb. | Quercus gambelii var. gambelii | Fagaceae
|
| QUWA2 | Quercus ×wagneri Gaynor | | Fagaceae
|
| QUWA | Quercus ×walteriana Ashe | | Fagaceae
|
| QUWI5 | Quercus wilcoxii Rydb. | Quercus chrysolepis var. chrysolepis | Fagaceae
|
| QUWI | Quercus ×willdenowiana (Dippel) Beissner, Schelle & Zabel (pro sp.) | | Fagaceae
|
| QUWIF | Quercus wislizeni A. DC. var. frutescens Engelm. | interior live oak | Fagaceae
|
| QUWIW | Quercus wislizeni A. DC. var. wislizeni | interior live oak | Fagaceae
|
| QUWI2 | Quercus wislizeni A. DC. | interior live oak | Fagaceae
|
| QUERC | Quercus L. | oak | Fagaceae
|
| QUSA4 | Quillaja saponaria Molina | soapbark | Rosaceae
|
| QUILL | Quillaja Molina | quillaja | Rosaceae
|
| QULO2 | Quincula lobata (Torr.) Raf. | Chinese lantern | Solanaceae
|
| QUINC | Quincula Raf. | quincula | Solanaceae
|
| QUIN10 | Quisqualis indica L. | Rangoon creeper | Combretaceae
|
| QUMU4 | Quisqualis mussaendiflora (Engl. & Diels) Exell. | | Combretaceae
|
| QUISQ | Quisqualis L. | Rangoon creeper | Combretaceae
|
| RARU3 | Racodium rupestre Pers. | | Uncertain Lichen Family
|
| RACOD | Racodium Pers.:Fr. | racodium | Uncertain Lichen Family
|
| RAAC4 | Racomitrium aciculare (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RAAF2 | Racomitrium affine (Schleich. ex Web. & Mohr) Lindb. | racomitrium moss | Grimmiaceae
|
| RAAQ2 | Racomitrium aquaticum (Brid. ex Schrad.) Brid. | aquatic racomitrium moss | Grimmiaceae
|
| RABR | Racomitrium brevipes Kindb. in Mac. | racomitrium moss | Grimmiaceae
|
| RABR2 | Racomitrium brevisetum Lindb. | racomitrium moss | Grimmiaceae
|
| RACAL5 | Racomitrium canescens (Hedw.) Brid. ssp. latifolium (C. Jens. in Lange & C. Jens.) Frisv. | Racomitrium canescens var. latifolium | Grimmiaceae
|
| RACAC5 | Racomitrium canescens (Hedw.) Brid. var. canescens | racomitrium moss | Grimmiaceae
|
| RACAL4 | Racomitrium canescens (Hedw.) Brid. var. latifolium C. Jens. | wideleaf racomitrium moss | Grimmiaceae
|
| RACAS2 | Racomitrium canescens (Hedw.) Brid. var. strictum Schlieph. in Limpr. | Racomitrium ericoides | Grimmiaceae
|
| RACA9 | Racomitrium canescens (Hedw.) Brid. f. epilosum | Racomitrium ericoides | Grimmiaceae
|
| RACA10 | Racomitrium canescens (Hedw.) Brid. f. ericoides | Racomitrium ericoides | Grimmiaceae
|
| RACA11 | Racomitrium canescens (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RADE6 | Racomitrium depressum Lesq. | racomitrium moss | Grimmiaceae
|
| RAEL3 | Racomitrium elongatum Ehrh. ex Frisv. | elongate racomitrium moss | Grimmiaceae
|
| RAER2 | Racomitrium ericoides (Web. ex Brid.) Brid. | racomitrium moss | Grimmiaceae
|
| RAFA6 | Racomitrium fasciculare (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RAHEA | Racomitrium heterostichum (Hedw.) Brid. var. affine (Schleich. ex Web. & Mohr) Lesq. | Racomitrium affine | Grimmiaceae
|
| RAHEA2 | Racomitrium heterostichum (Hedw.) Brid. var. alopecurum Hüb. | Racomitrium affine | Grimmiaceae
|
| RAHEG | Racomitrium heterostichum (Hedw.) Brid. var. gracilescens Bruch & Schimp. in B.S.G. | Racomitrium heterostichum | Grimmiaceae
|
| RAHEM | Racomitrium heterostichum (Hedw.) Brid. var. macounii (Kindb. in Mac.) G. Jones in Grout | Racomitrium macounii | Grimmiaceae
|
| RAHEM2 | Racomitrium heterostichum (Hedw.) Brid. var. microcarpon (Hedw.) Boul. | Racomitrium microcarpon | Grimmiaceae
|
| RAHEO | Racomitrium heterostichum (Hedw.) Brid. var. occidentale Ren. & Card. | Racomitrium occidentale | Grimmiaceae
|
| RAHER | Racomitrium heterostichum (Hedw.) Brid. var. ramulosum (Lindb.) Corb. | Racomitrium microcarpon | Grimmiaceae
|
| RAHES | Racomitrium heterostichum (Hedw.) Brid. var. sudeticum (Funck) Bauer | Racomitrium sudeticum | Grimmiaceae
|
| RAHE8 | Racomitrium heterostichum (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RAHY5 | Racomitrium hypnoides Lindb. | Racomitrium lanuginosum | Grimmiaceae
|
| RALAS | Racomitrium lanuginosum (Hedw.) Brid. var. subimberbe (Hartm.) Lindb. | Racomitrium lanuginosum | Grimmiaceae
|
| RALA70 | Racomitrium lanuginosum (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RALA8 | Racomitrium lawtonae Irel. | Lawton's racomitrium moss | Grimmiaceae
|
| RAMAA2 | Racomitrium macounii Kindb. in Mac. ssp. alpinum (Lawt.) Frisv. | Racomitrium macounii | Grimmiaceae
|
| RAMA9 | Racomitrium macounii Kindb. in Mac. | Macoun's racomitrium moss | Grimmiaceae
|
| RAMI8 | Racomitrium microcarpon (Hedw.) Brid. | racomitrium moss | Grimmiaceae
|
| RAMU4 | Racomitrium muticum (Kindb. in Mac.) Frisv. | racomitrium moss | Grimmiaceae
|
| RAOB4 | Racomitrium obesum Frisv. | racomitrium moss | Grimmiaceae
|
| RAOC2 | Racomitrium occidentale (Ren. & Card.) Ren. & Card. | western racomitrium moss | Grimmiaceae
|
| RAPA9 | Racomitrium pacificum Irel. & Spence | Pacific racomitrium moss | Grimmiaceae
|
| RAPA10 | Racomitrium panschii (C. Müll.) Kindb. | Pansch's racomitrium moss | Grimmiaceae
|
| RAPA11 | Racomitrium patens (Hedw.) Hüb. | Dryptodon patens | Grimmiaceae
|
| RAPY2 | Racomitrium pygmaeum Frisv. | pygmy racomitrium moss | Grimmiaceae
|
| RARA4 | Racomitrium ramulosum Lindb. | Racomitrium microcarpon | Grimmiaceae
|
| RASU10 | Racomitrium sudeticum (Funck) Bruch & Schimp. in B.S.G. f. alpinum | Racomitrium macounii | Grimmiaceae
|
| RASU11 | Racomitrium sudeticum (Funck) Bruch & Schimp. in B.S.G. f. americanum | Racomitrium macounii | Grimmiaceae
|
| RASU12 | Racomitrium sudeticum (Funck) Bruch & Schimp. in B.S.G. f. brevipes | Racomitrium brevipes | Grimmiaceae
|
| RASU13 | Racomitrium sudeticum (Funck) Bruch & Schimp. in B.S.G. f. macounii | Racomitrium macounii | Grimmiaceae
|
| RASU9 | Racomitrium sudeticum (Funck) Bruch & Schimp. in B.S.G. | racomitrium moss | Grimmiaceae
|
| RAVA3 | Racomitrium varium (Mitt.) Jaeg. | racomitrium moss | Grimmiaceae
|
| RAVE2 | Racomitrium venustum Frisv. | racomitrium moss | Grimmiaceae
|
| RACOM | Racomitrium Brid. | racomitrium moss | Grimmiaceae
|
| RATO | Racopilum tomentosum (Hedw.) Brid. | racopilum moss | Racopilaceae
|
| RACOP2 | Racopilum P. Beauv. | racopilum moss | Racopilaceae
|
| RAAR5 | Radicula armoracia (L.) B.L. Robins. | Armoracia rusticana | Brassicaceae
|