A new combination in South American Carex (Cyperaceae) and additional notes on the genus

Resumen

 A new combination in South American Carex, C. rupicola (Pedersen) G.A. Wheeler, is made here. This species occurs in eastern Argentina and southern Uruguay, where it grows in dry and rocky places on uplands. Additionally, the taxonomic status of four carices described as new by Hans H. Pfeiffer in 1921 is discussed. Of these, Carex feddeana H. Pfeiff. is recognized as a good species and the name is lectotypified. This species occurs in southeastern Brazil, Uruguay, eastern Paraguay, and northeastern Argentina. Pfeiffer's other three carices are here considered to be conspecific with earlier described taxa, and the names C. gynaecandra H. Pfeiff., C. decidua Boott var. caespitosa H. Pfeiff., and C. sphaerogyna Baker var. brasiliensis H. Pfeiff. are placed in synonymy under C. brasiliensis A. St. Hil., C. catharinensis Boeck., and C. purpureovaginata Boeck., respectively.