Syn.: Sanguisorba auriculata Scop., Sanguisorba major Gilib., Sanguisorba angustifolia Opiz, Poterium officinale (L.) A. Gray
Family: Rosaceae Juss.

Syn.: Sanicula canadensis var. marilandica (L.) Hitchc.
Family: Apiaceae Lindl.

Syn.: Pterosporopsis sanguinea Kuntze
Family: Ericaceae Juss.; Monotropaceae Nutt.

Syn.: Saururus cernuus f. submersus Gluck
Family: Saururaceae Rich. ex T. Lestib.

Syn.: Hirculus flagellaris Haw., Leptasea flagellaris Small
Family: Saxifragaceae Juss.

Syn.: Saxifraga boryi Boiss. et Heldr., Saxifraga carpathica N. Terracc., nom. illeg., Saxifraga coriophylla Griseb., Saxifraga pseudocaesia Rochel
Family: Saxifragaceae Juss.

Syn.: Micranthes occidentalis (S. Watson) Small, Saxifraga reflexa subsp. occidentalis (S. Watson) Hultén
Family: Saxifragaceae Juss.

Syn.: Saxifraga aizoon Jacq.
Family: Saxifragaceae Juss.

Syn.: Saxifraga cymosa Waldst. et Kit., nom. inval., Saxifraga heterophylla Sternb.
Family: Saxifragaceae Juss.

Syn.: Saxifraga gouanii f. cernagorica N.Terracc., Saxifraga media var. sibthorpiana Griseb., Saxifraga thessalica Schott
Family: Saxifragaceae Juss.

Family: Schizaeaceae Kaulf.

Syn.: Caesalpinia parahyba (Vell.) Allem., Cassia parahyba Vell., Schizolobium excelsum Vogel, Schizolobium glutinosum Tul., Schizolobium kellermanii Pittier, Schizolobium parahybum (Vell.) S. F. Blake, orth var.
Family: Caesalpiniaceae Klotzsch et Garcke; Fabaceae Lindl.

Syn.: Scirpus supinus L., Isolepis supina (L.) R. Br., Schoenoplectus melanospermus (C. A. Mey.) Grossh., Scirpus melanospermus C. A. Mey. in Mém.
Family: Cyperaceae Juss.

Syn.: Scutellaria caroliniana Lam., Scutellaria hyssopifolia L., Scutellaria polymorpha A.Ham.
Family: Lamiaceae Lindl.

Family: Crassulaceae J. St.-Hil.