| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| SIOCO | Silene occidentalis S. Wats. ssp. occidentalis | western catchfly | Caryophyllaceae
|
| SIOCN | Silene occidentalis S. Wats. var. nancta Jepson | Silene verecunda ssp. platyota var. platyota | Caryophyllaceae
|
| SIOC | Silene occidentalis S. Wats. | western catchfly | Caryophyllaceae
|
| SIOR6 | Silene oraria M.E. Peck | Silene douglasii var. oraria | Caryophyllaceae
|
| SIOR3 | Silene oregana S. Wats. | Oregon silene | Caryophyllaceae
|
| SIOV | Silene ovata Pursh | Blue Ridge catchfly | Caryophyllaceae
|
| SIPA9 | Silene pacifica Eastw. | Silene scouleri ssp. scouleri var. pacifica | Caryophyllaceae
|
| SIPAL | Silene parishii S. Wats. var. latifolia C.L. Hitchc. & Maguire | Parish's catchfly | Caryophyllaceae
|
| SIPAP | Silene parishii S. Wats. var. parishii | Parish's catchfly | Caryophyllaceae
|
| SIPAV | Silene parishii S. Wats. var. viscida C.L. Hitchc. & Maguire | Parish's catchfly | Caryophyllaceae
|
| SIPA3 | Silene parishii S. Wats. | Parish's catchfly | Caryophyllaceae
|
| SIPA4 | Silene parryi (S. Wats.) C.L. Hitchc. & Maguire | Parry's silene | Caryophyllaceae
|
| SIPE9 | Silene pectinata S. Wats. | Silene nuda ssp. nuda | Caryophyllaceae
|
| SIPE3 | Silene pendula L. | nodding catchfly | Caryophyllaceae
|
| SIPE8 | Silene pensylvanica Michx. | Silene caroliniana ssp. pensylvanica | Caryophyllaceae
|
| SIPE5 | Silene perlmanii W.L. Wagner, Herbst & Sohmer | cliffface catchfly | Caryophyllaceae
|
| SIPEM | Silene petersonii Maguire var. minor C.L. Hitchc. & Maguire | plateau catchfly | Caryophyllaceae
|
| SIPEP2 | Silene petersonii Maguire var. petersonii | plateau catchfly | Caryophyllaceae
|
| SIPE | Silene petersonii Maguire | plateau catchfly | Caryophyllaceae
|
| SIPL | Silene plankii C.L. Hitchc. & Maguire | Plank's catchfly | Caryophyllaceae
|
| SIPL2 | Silene platyota S. Wats. | Silene verecunda ssp. platyota var. platyota | Caryophyllaceae
|
| SIPO | Silene polypetala (Walt.) Fern. & Schub. | eastern fringed catchfly | Caryophyllaceae
|
| SIPR4 | Silene pratensis (Rafn) Godr. & Gren. | Silene latifolia ssp. alba | Caryophyllaceae
|
| SIPS2 | Silene pseudatocion Desf. | | Caryophyllaceae
|
| SIPU2 | Silene pulverulenta M.E. Peck | Silene hookeri ssp. pulverulenta | Caryophyllaceae
|
| SIPU3 | Silene pumilio (L.) Wulfen | Saponaria pumilio | Caryophyllaceae
|
| SIPU5 | Silene purpurata Greene | Silene repens ssp. purpurata | Caryophyllaceae
|
| SIRE5 | Silene rectiramea B.L. Robins. | Grand Canyon campion | Caryophyllaceae
|
| SIRE2 | Silene regia Sims | royal catchfly | Caryophyllaceae
|
| SIREA | Silene repens Patrin ex Pers. ssp. australis C.L. Hitchc. & Maguire | pink campion | Caryophyllaceae
|
| SIREP | Silene repens Patrin ex Pers. ssp. purpurata (Greene) C.L. Hitchc. & Maguire | pink campion | Caryophyllaceae
|
| SIREA3 | Silene repens Patrin ex Pers. var. australis (C.L. Hitchc. & Maguire) C.L. Hitchc. | Silene repens ssp. australis | Caryophyllaceae
|
| SIREC | Silene repens Patrin ex Pers. var. costata (Williams) Boivin | Silene scouleri ssp. scouleri var. scouleri | Caryophyllaceae
|
| SIRE3 | Silene repens Patrin ex Pers. | pink campion | Caryophyllaceae
|
| SIRO4 | Silene rotundifolia Nutt. | roundleaf catchfly | Caryophyllaceae
|
| SISA | Silene sargentii S. Wats. | Sargent's catchfly | Caryophyllaceae
|
| SISCL | Silene scaposa B.L. Robins. var. lobata C.L. Hitchc. & Maguire | Lost River silene | Caryophyllaceae
|
| SISCS | Silene scaposa B.L. Robins. var. scaposa | Blue Mountain catchfly | Caryophyllaceae
|
| SISC | Silene scaposa B.L. Robins. | Blue Mountain catchfly | Caryophyllaceae
|
| SISCG | Silene scouleri Hook. ssp. grandis (Eastw.) C.L. Hitchc. & Maguire | Silene scouleri ssp. scouleri var. scouleri | Caryophyllaceae
|
| SISCH | Silene scouleri Hook. ssp. hallii (S. Wats.) C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCC | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire var. concolor (Greene) C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCE | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire var. eglandulosa C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCG3 | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire var. grisea C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCL2 | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire var. leptophylla C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCP2 | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire var. pringlei (S. Wats.) C.L. Hitchc. & Maguire ex Kartesz & Gandhi | simple campion | Caryophyllaceae
|
| SISCP | Silene scouleri Hook. ssp. pringlei (S. Wats.) C.L. Hitchc. & Maguire | simple campion | Caryophyllaceae
|
| SISCP3 | Silene scouleri Hook. ssp. scouleri var. pacifica (Eastw.) C.L. Hitchc. | simple campion | Caryophyllaceae
|
| SISCS3 | Silene scouleri Hook. ssp. scouleri var. scouleri | simple campion | Caryophyllaceae
|
| SISCS2 | Silene scouleri Hook. ssp. scouleri | simple campion | Caryophyllaceae
|
| SISCM | Silene scouleri Hook. var. macounii (S. Wats.) Boivin | Silene parryi | Caryophyllaceae
|
| SISC7 | Silene scouleri Hook. | simple campion | Caryophyllaceae
|
| SISE2 | Silene seelyi Morton & J.W. Thompson | Seely's catchfly | Caryophyllaceae
|
| SISH2 | Silene shockleyi S. Wats. | Silene bernardina ssp. bernardina | Caryophyllaceae
|
| SISO2 | Silene soczaviana (Schischkin) Bocquet | boreal catchfly | Caryophyllaceae
|
| SISO3 | Silene sorensenis (Boivin) Bocquet | Sorensen's catchfly | Caryophyllaceae
|
| SISP2 | Silene spaldingii S. Wats. | Spalding's silene | Caryophyllaceae
|
| SISTS | Silene stellata (L.) Ait. f. var. scabrella Palmer & Steyermark | Silene stellata | Caryophyllaceae
|
| SIST | Silene stellata (L.) Ait. f. | widowsfrill | Caryophyllaceae
|
| SIST2 | Silene struthioloides Gray | alpine catchfly | Caryophyllaceae
|
| SISU3 | Silene subciliata B.L. Robins. | Louisiana catchfly | Caryophyllaceae
|
| SISU | Silene suksdorfii B.L. Robins. | Suksdorf's silene | Caryophyllaceae
|
| SITA | Silene taimyrensis (Tolm.) Bocquet | Taimyr catchfly | Caryophyllaceae
|
| SITA2 | Silene tayloriae (B.L. Robins.) Hult�n | Peel River catchfly | Caryophyllaceae
|
| SITE4 | Silene tetonensis A. Nels. | Silene parryi | Caryophyllaceae
|
| SITH | Silene thurberi S. Wats. | woolly catchfly | Caryophyllaceae
|
| SIUN | Silene uniflora Roth | sea campion | Caryophyllaceae
|
| SIURA3 | Silene uralensis (Rupr.) Bocquet ssp. apetala (L.) Bocquet | Silene uralensis ssp. uralensis | Caryophyllaceae
|
| SIURA | Silene uralensis (Rupr.) Bocquet ssp. attenuata (Farr) McNeill | apetalous catchfly | Caryophyllaceae
|
| SIURM | Silene uralensis (Rupr.) Bocquet ssp. montana (S. Wats.) McNeill | apetalous catchfly | Caryophyllaceae
|
| SIURO | Silene uralensis (Rupr.) Bocquet ssp. ogilviensis (Porsild) Brunton | apetalous catchfly | Caryophyllaceae
|
| SIURP | Silene uralensis (Rupr.) Bocquet ssp. porsildii Bocquet | Silene macrosperma | Caryophyllaceae
|
| SIURU | Silene uralensis (Rupr.) Bocquet ssp. uralensis | apetalous catchfly | Caryophyllaceae
|
| SIUR | Silene uralensis (Rupr.) Bocquet | apetalous catchfly | Caryophyllaceae
|
| SIVEA | Silene verecunda S. Wats. ssp. andersonii (Clokey) C.L. Hitchc. & Maguire | San Francisco campion | Caryophyllaceae
|
| SIVEE | Silene verecunda S. Wats. ssp. platyota (S. Wats.) C.L. Hitchc. & Maguire var. eglandulosa C.L. Hitchc. & Maguire | San Francisco campion | Caryophyllaceae
|
| SIVEP2 | Silene verecunda S. Wats. ssp. platyota (S. Wats.) C.L. Hitchc. & Maguire var. platyota (S. Wats.) Jepson | San Francisco campion | Caryophyllaceae
|
| SIVEP | Silene verecunda S. Wats. ssp. platyota (S. Wats.) C.L. Hitchc. & Maguire | San Francisco campion | Caryophyllaceae
|
| SIVEV | Silene verecunda S. Wats. ssp. verecunda | San Francisco campion | Caryophyllaceae
|
| SIVE | Silene verecunda S. Wats. | San Francisco campion | Caryophyllaceae
|
| SIVIH | Silene virginica L. var. hallensis A.L. & M.C. Pickens | Silene virginica var. virginica | Caryophyllaceae
|
| SIVIR | Silene virginica L. var. robusta Strausbaugh & Core | fire pink | Caryophyllaceae
|
| SIVIV | Silene virginica L. var. virginica | fire pink | Caryophyllaceae
|
| SIVI4 | Silene virginica L. | fire pink | Caryophyllaceae
|
| SIVI8 | Silene viscaria (L.) Jessen | Lychnis viscaria | Caryophyllaceae
|
| SIVU | Silene vulgaris (Moench) Garcke | maidenstears | Caryophyllaceae
|
| SIWAA2 | Silene wahlbergella Chowdhuri ssp. arctica (Fries) Hult�n | Silene uralensis ssp. uralensis | Caryophyllaceae
|
| SIWAA | Silene wahlbergella Chowdhuri ssp. attenuata (Farr) Hult�n | Silene uralensis ssp. attenuata | Caryophyllaceae
|
| SIWAM | Silene wahlbergella Chowdhuri ssp. montana (S. Wats.) Hult�n | Silene uralensis ssp. montana | Caryophyllaceae
|
| SIWA4 | Silene wahlbergella Chowdhuri | Silene uralensis ssp. uralensis | Caryophyllaceae
|
| SIWA3 | Silene watsonii B.L. Robins. | Silene sargentii | Caryophyllaceae
|
| SIWH | Silene wherryi Small | Silene caroliniana ssp. wherryi | Caryophyllaceae
|
| SIWI | Silene williamsii Britt. | Silene menziesii ssp. williamsii | Caryophyllaceae
|
| SIWR | Silene wrightii Gray | Wright's catchfly | Caryophyllaceae
|
| SILEN | Silene L. | catchfly | Caryophyllaceae
|
| SIAL | Silphium albiflorum Gray | white rosinweed | Asteraceae
|
| SIAN9 | Silphium angustum (Gray) Small | Silphium asteriscus var. angustatum | Asteraceae
|
| SIAS | Silphium asperrimum Hook. | Silphium radula | Asteraceae
|
| SIASA | Silphium asteriscus L. var. angustatum Gray | starry rosinweed | Asteraceae
|
| SIASA3 | Silphium asteriscus L. var. asteriscus | starry rosinweed | Asteraceae
|
| SIASD2 | Silphium asteriscus L. var. dentata (Ell.) Chapman | Silphium asteriscus var. laevicaule | Asteraceae
|