Centropodia forskaolii 
Cheatgrass 
Cherokee Sedge 
Chinese pennisetum 
chufa sedge 
Cipuropsis capituligera 
Cipuropsis hospitalis 
Clustered Bur-reed 
Colpodium biebersteinianum 
Common Club-Rush 
Common Cotton-Grass 
Common reed 
Common rush 
common rush 
Common spike-rush 
Common wheat or bread wheat 
Common Wild Oat 
Compact Brome 
Compact Rush 
Crested Wheatgrass 
Crimson fountaingrass 
Crithopsis 
Crypsis minuartioides 
Curly sedge