| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| QUNE | Quercus ×neopalmeri Sudworth ex Palmer | | Fagaceae
|
| QUNE2 | Quercus ×neotharpii A. Camus | | Fagaceae
|
| QUNE3 | Quercus ×nessiana Palmer | | Fagaceae
|
| QUNIH | Quercus nigra L. var. heterophylla (Ait.) Ashe | Quercus nigra | Fagaceae
|
| QUNI | Quercus nigra L. | water oak | Fagaceae
|
| QUNI2 | Quercus nitescens Rydb. | Quercus gambelii var. gambelii | Fagaceae
|
| QUNO | Quercus novomexicana (A. DC.) Rydb. | Quercus gambelii var. gambelii | Fagaceae
|
| QUNUC | Quercus nuttallii Palmer var. cachensis Palmer | Quercus texana | Fagaceae
|
| QUNU | Quercus nuttallii Palmer | Quercus texana | Fagaceae
|
| QUOB | Quercus oblongifolia Torr. | Mexican blue oak | Fagaceae
|
| QUOB2 | Quercus obtusa (Willd.) Ashe | Quercus laurifolia | Fagaceae
|
| QUOE | Quercus oerstediana R. Br. | Quercus garryana var. semota | Fagaceae
|
| QUOG | Quercus oglethorpensis Duncan | Oglethorpe oak | Fagaceae
|
| QUOR | Quercus ×organensis Trel. | | Fagaceae
|
| QUOV | Quercus ×oviedoensis Sarg. | | Fagaceae
|
| QUPA6 | Quercus pacifica Nixon & C.H. Muller | Channel Island scrub oak | Fagaceae
|
| QUPA5 | Quercus pagoda Raf. | cherrybark oak | Fagaceae
|
| QUPA11 | Quercus pagodifolia (Ell.) Ashe | Quercus pagoda | Fagaceae
|
| QUPA | Quercus ×palaeolithicola Trel. | | Fagaceae
|
| QUPA10 | Quercus palmeri Engelm. | Quercus dunnii | Fagaceae
|
| QUPA3 | Quercus ×palmeriana A. Camus | | Fagaceae
|
| QUPA2 | Quercus palustris Muenchh. | pin oak | Fagaceae
|
| QUPAP2 | Quercus parvula Greene var. parvula | Santa Cruz Island oak | Fagaceae
|
| QUPAS2 | Quercus parvula Greene var. shrevei (C.H. Muller) Nixon | Shreve oak | Fagaceae
|
| QUPAT | Quercus parvula Greene var. tamalpaisensis S.K. Langer | Tamalpais oak | Fagaceae
|
| QUPA8 | Quercus parvula Greene | coast oak | Fagaceae
|
| QUPA4 | Quercus ×pauciloba Rydb. (pro sp.) | | Fagaceae
|
| QUPE3 | Quercus persica Jaub. & Spach | Quercus brantii | Fagaceae
|
| QUPE2 | Quercus petraea (Mattuschka) Liebl. | durmast oak | Fagaceae
|
| QUPHL | Quercus phellos L. var. laurifolia (Michx.) Chapman | Quercus laurifolia | Fagaceae
|
| QUPH | Quercus phellos L. | willow oak | Fagaceae
|
| QUPI | Quercus ×pinetorum Moldenke | Quercus willdenowiana | Fagaceae
|
| QUPO | Quercus ×podophylla Trel. | | Fagaceae
|
| QUPO2 | Quercus polymorpha Schlecht. & Cham. | netleaf white oak | Fagaceae
|
| QUPO3 | Quercus ×porteri Trel. | Quercus hawkinsiae | Fagaceae
|
| QUPR3 | Quercus pricei Sudworth | Quercus agrifolia var. agrifolia | Fagaceae
|
| QUPRA | Quercus prinoides Willd. var. acuminata (Michx.) Gleason | Quercus muehlenbergii | Fagaceae
|
| QUPRR | Quercus prinoides Willd. var. rufescens Rehd. | Quercus prinoides | Fagaceae
|
| QUPR5 | Quercus prinoides Coult., non Willd. | Quercus muehlenbergii | Fagaceae
|
| QUPR | Quercus prinoides Willd. | dwarf chinkapin oak | Fagaceae
|
| QUPR2 | Quercus prinus L. | chestnut oak | Fagaceae
|
| QUPR4 | Quercus prinus auct. p.p. non L. | Quercus michauxii | Fagaceae
|
| QUPS | Quercus ×pseudomargarettiae Trel. (pro sp.) | | Fagaceae
|
| QUPU80 | Quercus pumila Walt. | running oak | Fagaceae
|
| QUPUV | Quercus pungens Liebm. var. vaseyana (Buckl.) C.H. Muller | Quercus vaseyana | Fagaceae
|
| QUPU | Quercus pungens Liebm. | pungent oak | Fagaceae
|
| QURE | Quercus ×rehderi Trel. | | Fagaceae
|
| QURE3 | Quercus reticulata Humb. & Bonpl. | Quercus rugosa | Fagaceae
|
| QURI3 | Quercus ×richteri Baenitz | Quercus coccinea var. coccinea | Fagaceae
|
| QURI | Quercus ×riparia Laughlin | | Fagaceae
|
| QURO | Quercus ×robbinsii Trel. | | Fagaceae
|
| QURO2 | Quercus robur L. | English oak | Fagaceae
|
| QURO3 | Quercus robusta C.H. Muller | robust oak | Fagaceae
|
| QURO4 | Quercus ×rolfsii Small (pro sp.) | | Fagaceae
|
| QURUA | Quercus rubra L. var. ambigua (Gray) Fern. | northern red oak | Fagaceae
|
| QURUB | Quercus rubra L. var. borealis (Michx. f.) Farw. | Quercus rubra var. ambigua | Fagaceae
|
| QURUR | Quercus rubra L. var. rubra | northern red oak | Fagaceae
|
| QURUT | Quercus rubra L. var. texana (Buckl.) Buckl. | Quercus texana | Fagaceae
|
| QURU | Quercus rubra L. | northern red oak | Fagaceae
|
| QURU2 | Quercus ×rudkinii Britt. (pro sp.) | | Fagaceae
|
| QURU4 | Quercus rugosa Née | netleaf oak | Fagaceae
|
| QURU3 | Quercus ×runcinata (A. DC.) Engelm. | | Fagaceae
|
| QUSA2 | Quercus sadleriana R. Br. | deer oak | Fagaceae
|
| QUSA7 | Quercus san-sabeana Buckl. | Quercus sinuata var. breviloba | Fagaceae
|
| QUSA3 | Quercus ×sargentii Rehd. | | Fagaceae
|
| QUSA | Quercus ×saulii Schneid. | | Fagaceae
|
| QUSC5 | Quercus schneckii Britt. | Quercus shumardii var. schneckii | Fagaceae
|
| QUSC | Quercus ×schochiana Dieck ex Palmer | | Fagaceae
|
| QUSC2 | Quercus ×schuettei Trel. | | Fagaceae
|
| QUSE | Quercus sessiliflora Salisb. | Quercus petraea | Fagaceae
|
| QUSH2 | Quercus ×shirlingii Bush ex Palmer & Steyermark | Quercus egglestonii | Fagaceae
|
| QUSH3 | Quercus shrevei C.H. Muller | Quercus parvula var. shrevei | Fagaceae
|
| QUSHA | Quercus shumardii Buckl. var. acerifolia Palmer | Quercus acerifolia | Fagaceae
|
| QUSHM | Quercus shumardii Buckl. var. microcarpa (Torr.) Shinners | Quercus texana | Fagaceae
|
| QUSHS | Quercus shumardii Buckl. var. schneckii (Britt.) Sarg. | Schneck oak | Fagaceae
|
| QUSHS2 | Quercus shumardii Buckl. var. shumardii | Shumard oak | Fagaceae
|
| QUSHS3 | Quercus shumardii Buckl. var. stenocarpa Laughlin | Shumard oak | Fagaceae
|
| QUSHT | Quercus shumardii Buckl. var. texana (Buckl.) Ashe | Quercus texana | Fagaceae
|
| QUSH | Quercus shumardii Buckl. | Shumard's oak | Fagaceae
|
| QUSI2 | Quercus similis Ashe | bottomland post oak | Fagaceae
|
| QUSIB | Quercus sinuata Walt. var. breviloba (Torr.) C.H. Muller | bastard oak | Fagaceae
|
| QUSIS2 | Quercus sinuata Walt. var. san-sabeana (Buckl.) Buckl. | Quercus sinuata var. breviloba | Fagaceae
|
| QUSIS | Quercus sinuata Walt. var. sinuata | bastard oak | Fagaceae
|
| QUSI | Quercus sinuata Walt. | bastard oak | Fagaceae
|
| QUSM | Quercus ×smallii Trel. | | Fagaceae
|
| QUSTA | Quercus stellata Wangenh. var. araniosa Sarg. | Quercus margarettiae | Fagaceae
|
| QUSTA2 | Quercus stellata Wangenh. var. attenuata Sarg. | Quercus stellata | Fagaceae
|
| QUSTB | Quercus stellata Wangenh. var. boyntonii (Beadle) Sarg. | Quercus boyntonii | Fagaceae
|
| QUSTM | Quercus stellata Wangenh. var. margarettiae (Ashe ex Small) Sarg. | Quercus margarettiae | Fagaceae
|
| QUSTM3 | Quercus stellata Wangenh. var. mississippiensis (Ashe) Little | Quercus similis | Fagaceae
|
| QUSTP | Quercus stellata Wangenh. var. paludosa Sarg. | Quercus similis | Fagaceae
|
| QUSTP2 | Quercus stellata Wangenh. var. parviloba Sarg. | Quercus stellata | Fagaceae
|
| QUST | Quercus stellata Wangenh. | post oak | Fagaceae
|
| QUST2 | Quercus ×stelloides Palmer | | Fagaceae
|
| QUST3 | Quercus ×sterilis Trel. ex Palmer | | Fagaceae
|
| QUST4 | Quercus ×sterretii Trel. | | Fagaceae
|
| QUSU4 | Quercus ×subconvexa Tucker | | Fagaceae
|
| QUSU5 | Quercus suber L. | cork oak | Fagaceae
|
| QUSU6 | Quercus ×subfalcata Trel. | | Fagaceae
|
| QUSU2 | Quercus ×subintegra (Engelm.) Trel. | | Fagaceae
|
| QUSU9 | Quercus ×sublaurifolia Trel. ex Palmer | Quercus atlantica | Fagaceae
|