| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| SCSA5 | Scutellaria saxatilis Riddell | smooth rock skullcap | Lamiaceae
|
| SCSEM | Scutellaria serrata Andr. var. montana (Chapman) Penl. | Scutellaria montana | Lamiaceae
|
| SCSE5 | Scutellaria serrata Andr. | showy skullcap | Lamiaceae
|
| SCSI | Scutellaria siphocamyploides Vatke | grayleaf skullcap | Lamiaceae
|
| SCTE4 | Scutellaria tessellata Epling | Scutellaria potosina ssp. potosina var. tessellata | Lamiaceae
|
| SCTE15 | Scutellaria texana B.L. Turner | Texas skullcap | Lamiaceae
|
| SCTH | Scutellaria thieretii Shinners | Thieret's skullcap | Lamiaceae
|
| SCTUA | Scutellaria tuberosa Benth. ssp. australis (Jepson) Epling | Scutellaria tuberosa | Lamiaceae
|
| SCTUS2 | Scutellaria tuberosa Benth. ssp. similis (Jepson) Epling | Scutellaria tuberosa | Lamiaceae
|
| SCTUS | Scutellaria tuberosa Benth. var. similis Jepson | Scutellaria tuberosa | Lamiaceae
|
| SCTU2 | Scutellaria tuberosa Benth. | Danny's skullcap | Lamiaceae
|
| SCVE5 | Scutellaria veronicifolia Rydb. | Scutellaria angustifolia ssp. angustifolia | Lamiaceae
|
| SCWR2 | Scutellaria wrightii Gray | Wright's skullcap | Lamiaceae
|
| SCWR4 | Scutellaria wrightii auct. non Gray | Scutellaria resinosa | Lamiaceae
|
| SCUTE | Scutellaria L. | skullcap | Lamiaceae
|
| SCMI12 | Scutula miliaris (Wallr.) Trevisan | | Micareaceae
|
| SCST8 | Scutula stereocaulorum (Ach.) Korber | | Micareaceae
|
| SCTU3 | Scutula tuberculosa (Th. Fr.) Rehm | Scutula miliaris | Micareaceae
|
| SCUTU | Scutula Tul. | scutula | Micareaceae
|
| SCJA | Scybalium jamaicense (Sw.) Schott & Endl. | John crownose | Balanophoraceae
|
| SCYBA | Scybalium Schott & Endl. | scybalium | Balanophoraceae
|
| SCHY5 | Scyphiphora hydrophyllacea Gaertn. | | Rubiaceae
|
| SCYPH | Scyphiphora Gaertn. f. | | Rubiaceae
|
| SEBI9 | Sebastiania bilocularis S. Wats. | arrow poision plant | Euphorbiaceae
|
| SECO7 | Sebastiania corniculata (Vahl) Muell.-Arg. | hato tejas | Euphorbiaceae
|
| SEFR | Sebastiania fruticosa (Bartr.) Fern. | Gulf Sebastian-bush | Euphorbiaceae
|
| SELI7 | Sebastiania ligustrina (Michx.) Muell.-Arg. | Sebastiania fruticosa | Euphorbiaceae
|
| SEBAS2 | Sebastiania Spreng. | Sebastian-bush | Euphorbiaceae
|
| SERI5 | Sebesten rickseckeri (Millsp.) Britt. | Cordia rickseckeri | Boraginaceae
|
| SESE12 | Sebesten sebestena (L.) Britt. ex Small | Cordia sebestena | Boraginaceae
|
| SECE | Secale cereale L. | cereal rye | Poaceae
|
| SEMO | Secale ?montanum Guss. | Secale cereale | Poaceae
|
| SEOR8 | Secale orientale L. | Eremopyrum orientale | Poaceae
|
| SECAL | Secale L. | rye | Poaceae
|
| SEED | Sechium edule (Jacq.) Sw. | chayote | Cucurbitaceae
|
| SECHI | Sechium P. Br. | sechium | Cucurbitaceae
|
| SEGE2 | Secoligia geoica (Wahlenb. ex Ach.) Korber | Gyalecta geoica | Gyalectaceae
|
| SEHI4 | Secula histrix (Poir.) Small p.p. | Aeschynomene histrix var. incana | Fabaceae
|
| SEVI9 | Secula viscidula (Michx.) Small | Aeschynomene viscidula | Fabaceae
|
| SEDI6 | Securidaca diversifolia (L.) Blake | Easter flower | Polygalaceae
|
| SEVI5 | Securidaca virgata Sw. | bejuco de sopla | Polygalaceae
|
| SEVO | Securidaca volubilis L. | Dalbergia monetaria | Fabaceae
|
| SECUR | Securidaca L. | securidaca | Polygalaceae
|
| SESE80 | Securigera securidaca (L.) O. Deg. & Dorf. | Coronilla securidaca | Fabaceae
|
| SEVA4 | Securigera varia (L.) Lassen | Coronilla varia | Fabaceae
|
| SEAC3 | Securinega acidoton (L.) Fawcett & Rendle | Flueggea acidoton | Euphorbiaceae
|
| SECO6 | Sedella congdonii (Eastw.) Britt. & Rose | Congdon's mock stonecrop | Crassulaceae
|
| SELE7 | Sedella leiocarpa H.K. Sharsmith | Lake County mock stonecrop | Crassulaceae
|
| SEPE3 | Sedella pentandra H.K. Sharsmith | Mt. Hamilton mock stonecrop | Crassulaceae
|
| SEPU4 | Sedella pumila (Benth.) Britt. & Rose | Sierra mock stonecrop | Crassulaceae
|
| SEDEL | Sedella Britt. & Rose | mock stonecrop | Crassulaceae
|
| SEAC | Sedum acre L. | goldmoss stonecrop | Crassulaceae
|
| SEAI80 | Sedum aizoon L. | Aizoon stonecrop | Crassulaceae
|
| SEAL9 | Sedum alaskanum (Rose) Rose ex Hutchinson | Rhodiola integrifolia ssp. integrifolia | Crassulaceae
|
| SEAL2 | Sedum albomarginatum Clausen | Feather River stonecrop | Crassulaceae
|
| SEAL3 | Sedum alboroseum Baker | Hylotelephium erythrostictum | Crassulaceae
|
| SEAL | Sedum album L. | white stonecrop | Crassulaceae
|
| SEAN5 | Sedum anopetalum DC. | Sedum ochroleucum | Crassulaceae
|
| SEBO2 | Sedum borschii (Clausen) Clausen | Sedum leibergii | Crassulaceae
|
| SECI4 | Sedum ciliosum T.J. Howell | Sedum radiatum ssp. ciliosum | Crassulaceae
|
| SECO | Sedum cockerellii Britt. | Cockerell's stonecrop | Crassulaceae
|
| SECY5 | Sedum cymosum (Nutt.) Fr�d. | Diamorpha smallii | Crassulaceae
|
| SEDE | Sedum debile S. Wats. | orpine stonecrop | Crassulaceae
|
| SEDE8 | Sedum dendroideum Moc. & Sess� ex A. DC. | tree stonecrop | Crassulaceae
|
| SEDI | Sedum divergens S. Wats. | Pacific stonecrop | Crassulaceae
|
| SEDI10 | Sedum divericatum S. Wats. | Sedum leibergii | Crassulaceae
|
| SEDOC | Sedum douglasii Hook. ssp. ciliosum (T.J. Howell) Clausen | Sedum radiatum ssp. ciliosum | Crassulaceae
|
| SEDOR | Sedum douglasii Hook. ssp. radiatum (S. Wats.) Clausen | Sedum radiatum ssp. radiatum | Crassulaceae
|
| SEDO3 | Sedum douglasii Hook. | Sedum stenopetalum ssp. stenopetalum | Crassulaceae
|
| SEEA2 | Sedum eastwoodiae (Britt.) Berger | Red Mountain stonecrop | Crassulaceae
|
| SEEL3 | Sedum ellacombianum Praeger | Sedum kamtschaticum ssp. ellacombianum | Crassulaceae
|
| SEER6 | Sedum erythrostictum Miq. | Hylotelephium erythrostictum | Crassulaceae
|
| SEFA2 | Sedum fabaria W.D.J. Koch | Hylotelephium telephium ssp. fabaria | Crassulaceae
|
| SEGL6 | Sedum glanduliferum (Henderson) M.E. Peck | Sedum moranii | Crassulaceae
|
| SEGL3 | Sedum glaucophyllum Clausen | cliff stonecrop | Crassulaceae
|
| SEGR | Sedum griffithsii Rose | Sedum cockerellii | Crassulaceae
|
| SEHA | Sedum havardii Rose | Havard's stonecrop | Crassulaceae
|
| SEHE5 | Sedum heckneri M.E. Peck | Sedum laxum ssp. heckneri | Crassulaceae
|
| SEHI | Sedum hispanicum L. | Spanish stonecrop | Crassulaceae
|
| SEINL | Sedum integrifolium (Raf.) A. Nels. ssp. leedyi (Rosendahl & Moore) Clausen | Rhodiola integrifolia ssp. leedyi | Crassulaceae
|
| SEINN | Sedum integrifolium (Raf.) A. Nels. ssp. neomexicanum (Britt.) Clausen | Rhodiola integrifolia ssp. neomexicana | Crassulaceae
|
| SEINP | Sedum integrifolium (Raf.) A. Nels. ssp. procerum Clausen | Rhodiola integrifolia ssp. procera | Crassulaceae
|
| SEIN4 | Sedum integrifolium (Raf.) A. Nels. | Rhodiola integrifolia ssp. integrifolia | Crassulaceae
|
| SEKAE | Sedum kamtschaticum Fisch. & C.A. Mey. ssp. ellacombianum (Praeger) Clausen | orange stonecrop | Crassulaceae
|
| SEKA | Sedum kamtschaticum Fisch. & C.A. Mey. | orange stonecrop | Crassulaceae
|
| SELAL | Sedum lanceolatum Torr. ssp. lanceolatum | spearleaf stonecrop | Crassulaceae
|
| SELAN2 | Sedum lanceolatum Torr. ssp. nesioticum (G.N. Jones) Clausen | spearleaf stonecrop | Crassulaceae
|
| SELAS | Sedum lanceolatum Torr. ssp. subalpinum (Blank.) Clausen | subalpine stonecrop | Crassulaceae
|
| SELAN3 | Sedum lanceolatum Torr. var. nesioticum (G.N. Jones) C.L. Hitchc. | Sedum lanceolatum ssp. nesioticum | Crassulaceae
|
| SELAR2 | Sedum lanceolatum Torr. var. rupicola (G.N. Jones) C.L. Hitchc. | Sedum rupicola | Crassulaceae
|
| SELA | Sedum lanceolatum Torr. | spearleaf stonecrop | Crassulaceae
|
| SELAE | Sedum laxum (Britt.) Berger ssp. eastwoodiae (Britt.) Clausen | Sedum eastwoodiae | Crassulaceae
|
| SELAF | Sedum laxum (Britt.) Berger ssp. flavidum Denton | roseflower stonecrop | Crassulaceae
|
| SELAH | Sedum laxum (Britt.) Berger ssp. heckneri (M.E. Peck) Clausen | Heckner's stonecrop | Crassulaceae
|
| SELAL3 | Sedum laxum (Britt.) Berger ssp. latifolium Clausen | Sedum laxum ssp. laxum | Crassulaceae
|
| SELAL2 | Sedum laxum (Britt.) Berger ssp. laxum | roseflower stonecrop | Crassulaceae
|
| SELAP | Sedum laxum (Britt.) Berger ssp. perplexum Clausen | Sedum laxum ssp. laxum | Crassulaceae
|
| SELAR3 | Sedum laxum (Britt.) Berger ssp. retusum (Rose) Clausen | Sedum obtusatum ssp. retusum | Crassulaceae
|
| SELA2 | Sedum laxum (Britt.) Berger | roseflower stonecrop | Crassulaceae
|
| SELET | Sedum leibergii Britt. var. typicum Clausen | Sedum leibergii | Crassulaceae
|
| SELE | Sedum leibergii Britt. | Leiberg stonecrop | Crassulaceae
|