| [16434] Nitzschia sigmatella var. minor | Appellations de Taxon | 16434 |
| [16435] Nitzschia sigmatella var. pusilla | Appellations de Taxon | 16435 |
| [16436] Navicula subgrimmei | Appellations de Taxon | 16436 |
| [16437] Navicula subagnita | Appellations de Taxon | 16437 |
| [16439] Nupela silvahercynia | Appellations de Taxon | 16439 |
| [1644] Potamogeton compressus | Appellations de Taxon | 1644 |
| [16440] Navicula schubartii | Appellations de Taxon | 16440 |
| [16441] Navicula schwabei | Appellations de Taxon | 16441 |
| [16442] Nitzschia spathulata var. hyalina | Appellations de Taxon | 16442 |
| [16443] Navicula sibirica | Appellations de Taxon | 16443 |
| [16444] Navicula suspica | Appellations de Taxon | 16444 |
| [16445] Navicula sieminskiae | Appellations de Taxon | 16445 |
| [16446] Nitzschia sigma var. intercedens | Appellations de Taxon | 16446 |
| [16447] Naviculadicta schneckenburgeri | Appellations de Taxon | 16447 |
| [16448] Navicula skuae | Appellations de Taxon | 16448 |
| [16449] Nitzschia sublanceolata | Appellations de Taxon | 16449 |
| [1645] Potamogeton crispus | Appellations de Taxon | 1645 |
| [16450] Navicula salebrosa | Appellations de Taxon | 16450 |
| [16451] Navicula supralitoralis | Appellations de Taxon | 16451 |
| [16452] Nitzschia strelnikovae | Appellations de Taxon | 16452 |
| [16453] Navicula sublyrata | Appellations de Taxon | 16453 |
| [16454] Navicula smeerenburgensis | Appellations de Taxon | 16454 |
| [16455] Navicula submuticoides | Appellations de Taxon | 16455 |
| [16456] Navicula semenoides | Appellations de Taxon | 16456 |
| [16457] Navicula semifasciata | Appellations de Taxon | 16457 |
| [16458] Navicula submuralis abnormal form | Appellations de Taxon | 16458 |
| [16459] Navicula semihyalina | Appellations de Taxon | 16459 |
| [1646] Potamogeton friesii | Appellations de Taxon | 1646 |
| [16460] Navicula semilyrata | Appellations de Taxon | 16460 |
| [16461] Nitzschia spinifera | Appellations de Taxon | 16461 |
| [16462] Navicula sancti-naumii | Appellations de Taxon | 16462 |
| [16463] Nitzschia semirobusta morphotype minor | Appellations de Taxon | 16463 |
| [16464] Navicula seminuda | Appellations de Taxon | 16464 |
| [16465] Navicula subnympharum | Appellations de Taxon | 16465 |
| [16466] Nitzschia socialis | Appellations de Taxon | 16466 |
| [16467] Nitzschia socialis var. baltica | Appellations de Taxon | 16467 |
| [16468] Navicula septifera | Appellations de Taxon | 16468 |
| [16469] Navicula sphagnophila | Appellations de Taxon | 16469 |
| [1647] Potamogeton gramineus | Appellations de Taxon | 1647 |
| [16470] Nitzschia spathulata | Appellations de Taxon | 16470 |
| [16471] Navicula sponsa | Appellations de Taxon | 16471 |
| [16472] Navicula septaeoides | Appellations de Taxon | 16472 |
| [16473] Navicula seippiana | Appellations de Taxon | 16473 |
| [16474] Navicula spirata | Appellations de Taxon | 16474 |
| [16475] Navicula spissata | Appellations de Taxon | 16475 |
| [16476] Nitzschia serpenticola | Appellations de Taxon | 16476 |
| [16477] Nitzschia schiellerupii | Appellations de Taxon | 16477 |
| [16478] Navicula subarvensis | Appellations de Taxon | 16478 |
| [16479] Nitzschia subsalsa | Appellations de Taxon | 16479 |
| [1648] Potamogeton helveticus | Appellations de Taxon | 1648 |