| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| SOARF | Sophora arizonica S. Wats. ssp. formosa (Kearney & Peebles) Yakovlev | Sophora arizonica | Fabaceae
|
| SOARF2 | Sophora arizonica S. Wats. var. formosa (Kearney & Peebles) Tsoong | Sophora arizonica | Fabaceae
|
| SOAR3 | Sophora arizonica S. Wats. | Arizona necklacepod | Fabaceae
|
| SOCHC | Sophora chrysophylla (Salisb.) Seem. ssp. circularis Chock | Sophora chrysophylla | Fabaceae
|
| SOCHG | Sophora chrysophylla (Salisb.) Seem. ssp. glabrata (Gray) Chock | Sophora chrysophylla | Fabaceae
|
| SOCHU | Sophora chrysophylla (Salisb.) Seem. ssp. unifoliata (Rock) Chock | Sophora chrysophylla | Fabaceae
|
| SOCHE2 | Sophora chrysophylla (Salisb.) Seem. var. elliptica Chock | Sophora chrysophylla | Fabaceae
|
| SOCHG3 | Sophora chrysophylla (Salisb.) Seem. var. glabrata (Gray) Chock | Sophora chrysophylla | Fabaceae
|
| SOCHG4 | Sophora chrysophylla (Salisb.) Seem. var. grisea (O. Deg. & Sherff) Chock | Sophora chrysophylla | Fabaceae
|
| SOCHK3 | Sophora chrysophylla (Salisb.) Seem. var. kanaioensis Chock | Sophora chrysophylla | Fabaceae
|
| SOCHK4 | Sophora chrysophylla (Salisb.) Seem. var. kauensis Chock | Sophora chrysophylla | Fabaceae
|
| SOCHL2 | Sophora chrysophylla (Salisb.) Seem. var. lanaiensis Chock | Sophora chrysophylla | Fabaceae
|
| SOCHM | Sophora chrysophylla (Salisb.) Seem. var. makuaensis Chock | Sophora chrysophylla | Fabaceae
|
| SOCHO2 | Sophora chrysophylla (Salisb.) Seem. var. ovata Chock | Sophora chrysophylla | Fabaceae
|
| SOCHU2 | Sophora chrysophylla (Salisb.) Seem. var. unifoliata (Rock) Chock | Sophora chrysophylla | Fabaceae
|
| SOCH | Sophora chrysophylla (Salisb.) Seem. | mamani | Fabaceae
|
| SOFO | Sophora formosa Kearney & Peebles | Sophora arizonica | Fabaceae
|
| SOGYG | Sophora gypsophila B.L. Turner & Powell var. guadalupensis B.L. Turner & Powell | Guadalupe Mountain necklacepod | Fabaceae
|
| SOGY80 | Sophora gypsophila B.L. Turner & Powell | Guadalupe Mountain necklacepod | Fabaceae
|
| SOJA6 | Sophora japonica L. | Japanese pagoda tree | Fabaceae
|
| SOKE | Sophora kentukea Dum.-Cours. | Cladrastis kentukea | Fabaceae
|
| SOLE3 | Sophora leachiana M.E. Peck | western necklacepod | Fabaceae
|
| SOLI2 | Sophora littoralis Schrad. | Sophora tomentosa var. littoralis | Fabaceae
|
| SOMI11 | Sophora microphylla Aiton | kowhai | Fabaceae
|
| SONU | Sophora nuttalliana B.L. Turner | silky sophora | Fabaceae
|
| SOSE3 | Sophora secundiflora (Ortega) Lag. ex DC. | mescal bean | Fabaceae
|
| SOSE8 | Sophora sericea Nutt. | Sophora nuttalliana | Fabaceae
|
| SOST4 | Sophora stenophylla Gray | fringeleaf necklacepod | Fabaceae
|
| SOTOB | Sophora tomentosa L. ssp. bahamensis Yakovlev | Sophora tomentosa var. truncata | Fabaceae
|
| SOTOL2 | Sophora tomentosa L. ssp. littoralis (Schrad.) Yakovlev | Sophora tomentosa var. littoralis | Fabaceae
|
| SOTOO2 | Sophora tomentosa L. ssp. occidentalis (L.) Brummitt | Sophora tomentosa var. occidentalis | Fabaceae
|
| SOTOL | Sophora tomentosa L. var. littoralis (Schrad.) Benth. | yellow necklacepod | Fabaceae
|
| SOTOO | Sophora tomentosa L. var. occidentalis (L.) Isely | yellow necklacepod | Fabaceae
|
| SOTOT | Sophora tomentosa L. var. truncata Torr. & Gray | yellow necklacepod | Fabaceae
|
| SOTO3 | Sophora tomentosa L. | yellow necklacepod | Fabaceae
|
| SOPHO | Sophora L. | necklacepod | Fabaceae
|
| SOHI8 | Sophronanthe hispida Benth. ex Lindl. | Gratiola hispida | Scrophulariaceae
|
| SOPI4 | Sophronanthe pilosa (Michx.) Small | Gratiola pilosa | Scrophulariaceae
|
| SOAR5 | Sorbaria arborea Schneid. | giant false spiraea | Rosaceae
|
| SOSO2 | Sorbaria sorbifolia (L.) A. Braun | false spiraea | Rosaceae
|
| SORBA | Sorbaria (Ser. ex DC.) A. Braun | false spiraea | Rosaceae
|
| SOAM3 | Sorbus americana Marsh. | American mountain ash | Rosaceae
|
| SOARA3 | Sorbus arbutifolia (L.) Heynh. var. atropurpurea (Britt.) Schneid. | Photinia floribunda | Rosaceae
|
| SOAR8 | Sorbus arbutifolia (L.) Heynh. | Photinia pyrifolia | Rosaceae
|
| SOAU | Sorbus aucuparia L. | European mountain ash | Rosaceae
|
| SOCA8 | Sorbus californica Greene | California mountain ash | Rosaceae
|
| SOCA15 | Sorbus cascadensis G.N. Jones | Sorbus scopulina var. cascadensis | Rosaceae
|
| SODEG | Sorbus decora (Sarg.) Schneid. var. groenlandica (Schneid.) G.N. Jones | Sorbus groenlandica | Rosaceae
|
| SODE3 | Sorbus decora (Sarg.) Schneid. | northern mountain ash | Rosaceae
|
| SODU2 | Sorbus dumosa Greene | Arizona mountain ash | Rosaceae
|
| SOGR2 | Sorbus groenlandica (Schneid.) A.& D. L�ve | Greenland mountain ash | Rosaceae
|
| SOHY3 | Sorbus hybrida L. | oakleaf mountain ash | Rosaceae
|
| SOME5 | Sorbus melanocarpa (Michx.) Heynh. | Photinia melanocarpa | Rosaceae
|
| SOOC3 | Sorbus occidentalis (S. Wats.) Greene | Sorbus sitchensis var. grayi | Rosaceae
|
| SOPI3 | Sorbus pinnatifida (Ehrh.) Bean | Sorbus thuringiaca | Rosaceae
|
| SOSA3 | Sorbus sambucifolia (Cham. & Schlecht.) M. Roemer | Siberian mountain ash | Rosaceae
|
| SOSCC | Sorbus scopulina Greene var. cascadensis (G.N. Jones) C.L. Hitchc. | Cascade mountain ash | Rosaceae
|
| SOSCS | Sorbus scopulina Greene var. scopulina | Greene's mountain ash | Rosaceae
|
| SOSC2 | Sorbus scopulina Greene | Greene's mountain ash | Rosaceae
|
| SOSIC2 | Sorbus sitchensis M. Roemer ssp. californica (Greene) Abrams | Sorbus californica | Rosaceae
|
| SOSIG3 | Sorbus sitchensis M. Roemer ssp. grayi (Wenzig) Calder & Taylor | Sorbus sitchensis var. grayi | Rosaceae
|
| SOSIG | Sorbus sitchensis M. Roemer var. grayi (Wenzig) C.L. Hitchc. | western mountain ash | Rosaceae
|
| SOSIS2 | Sorbus sitchensis M. Roemer var. sitchensis | Sitka mountain ash | Rosaceae
|
| SOSI2 | Sorbus sitchensis M. Roemer | western mountain ash | Rosaceae
|
| SOTH | Sorbus �thuringiaca (Ilse) Fritsch | | Rosaceae
|
| SOTO9 | Sorbus torminalis (L.) Crantz | checkertree | Rosaceae
|
| SORBU | Sorbus L. | mountain ash | Rosaceae
|
| SOAP | Sorghastrum apalachicolense D.W. Hall | Sorghastrum elliottii | Poaceae
|
| SOAV2 | Sorghastrum avenaceum (Michx.) Nash | Sorghastrum nutans | Poaceae
|
| SOEL3 | Sorghastrum elliottii (C. Mohr) Nash | slender Indiangrass | Poaceae
|
| SONU2 | Sorghastrum nutans (L.) Nash | Indiangrass | Poaceae
|
| SOPA11 | Sorghastrum parviflorum auct. non (Desv.) A.S. Hitchc. & Chase | Sorghastrum setosum | Poaceae
|
| SOSE5 | Sorghastrum secundum (Ell.) Nash | lopsided Indiangrass | Poaceae
|
| SOSE6 | Sorghastrum setosum (Griseb.) A.S. Hitchc. | sandysoil Indiangrass | Poaceae
|
| SOST5 | Sorghastrum stipoides (Kunth) Nash | needle Indiangrass | Poaceae
|
| SORGH | Sorghastrum Nash | Indiangrass | Poaceae
|
| SOAE3 | Sorghum aethiopicum (Hackel) Rupr. ex Stapf | Sorghum bicolor ssp. arundinaceum | Poaceae
|
| SOAL | Sorghum almum Parodi | Columbus grass | Poaceae
|
| SOAR7 | Sorghum arundinaceum (Desv.) Stapf | Sorghum bicolor ssp. arundinaceum | Poaceae
|
| SOBIA | Sorghum bicolor (L.) Moench ssp. arundinaceum (Desv.) de Wet & Harlan | common wild sorghum | Poaceae
|
| SOBIB | Sorghum bicolor (L.) Moench ssp. bicolor | grain sorghum | Poaceae
|
| SOBID | Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet & Harlan | Sudangrass | Poaceae
|
| SOBIA2 | Sorghum bicolor (L.) Moench var. aethiopicum (Hack.) de Wet & Huckabay | Sorghum bicolor ssp. arundinaceum | Poaceae
|
| SOBIC | Sorghum bicolor (L.) Moench var. caffrorum (Retz.) Mohlenbrock | Sorghum bicolor ssp. bicolor | Poaceae
|
| SOBID2 | Sorghum bicolor (L.) Moench var. drummondii (Nees ex Steud.) Mohlenbrock | Sorghum bicolor ssp. drummondii | Poaceae
|
| SOBIS | Sorghum bicolor (L.) Moench var. sudanense (Piper) A.S. Hitchc. | Sorghum bicolor ssp. drummondii | Poaceae
|
| SOBIV | Sorghum bicolor (L.) Moench var. virgatum (Hack.) de Wet & Huckabay | Sorghum bicolor ssp. arundinaceum | Poaceae
|
| SOBI2 | Sorghum bicolor (L.) Moench | sorghum | Poaceae
|
| SOCA14 | Sorghum caffrorum (Retz.) Beauv. | Sorghum bicolor ssp. bicolor | Poaceae
|
| SOCE80 | Sorghum cernuum (Ard.) Host | Sorghum bicolor ssp. bicolor | Poaceae
|
| SODOT | Sorghum dochna (Forsk.) Snowden var. technicum (Koern.) Snowden | Sorghum bicolor ssp. bicolor | Poaceae
|
| SODO2 | Sorghum dochna (Forsk.) Snowden | Sorghum bicolor ssp. bicolor | Poaceae
|
| SODR3 | Sorghum drummondii (Nees ex Steud.) Millsp. & Chase p.p. | Sorghum bicolor ssp. bicolor | Poaceae
|
| SODR3 | Sorghum drummondii (Nees ex Steud.) Millsp. & Chase p.p. | Sorghum bicolor ssp. drummondii | Poaceae
|
| SODU4 | Sorghum durra (Forsk.) Stapf | Sorghum bicolor ssp. bicolor | Poaceae
|
| SOGU3 | Sorghum guineense Stapf | Sorghum bicolor | Poaceae
|
| SOHA | Sorghum halepense (L.) Pers. | Johnsongrass | Poaceae
|
| SOLA2 | Sorghum lanceolatum Stapf | Sorghum bicolor ssp. arundinaceum | Poaceae
|
| SOMI10 | Sorghum miliaceum (Roxb.) Snowden | Sorghum halepense | Poaceae
|
| SONE7 | Sorghum nervosum Besser ex Schultes | Sorghum bicolor | Poaceae
|
| SOPR3 | Sorghum propinquum (Kunth) Hitchc. | sorghum | Poaceae
|