| Cyperus glandulosus Rolfe, 1882 |
| Cyperus glareosus Liebm., 1850 |
| Cyperus glaucus Steud., 1854 |
| Cyperus glaucus var. gracilis Boeckeler, 1870 |
| Cyperus globulosus Aubl., 1775 |
| Cyperus gonzaleziae G.C. Tucker, 2022 |
| Cyperus gracilescens Schult., 1824 |
| Cyperus gracilis Link, 1820 |
| Cyperus granadinus Liebm., 1850 |
| Cyperus guadalajaranus M.E. Jones, 1933 |
| Cyperus guatemalensis Gand., 1919 |
| Cyperus haenkei J. Presl & C. Presl, 1830 |
| Cyperus hartii Boeckeler, 1888 |
| Cyperus haspan L., 1753 |
| Cyperus haspan f. coarctatus (Nees) Osten, 1931 |
| Cyperus haspan subsp. juncoides (Lam.) Kük., 1926 |
| Cyperus haspan var. americanus Boeckeler, 1868 |
| Cyperus haspan var. coarctatus Nees, 1842 |
| Cyperus haspan var. riparius (Schrad. ex Nees) Kük., 1936 |
| Cyperus hayesii (C.B. Clarke) Standl., 1925 |