Cyperus odoratus Linnaeus var. odoratus . Phen: Jul-Sep. Hab: Low fields, marshes, ditches, sandbars. Dist: Pantropical, north in North America to MA, se. ME, ON, MN, KS, NM, AZ, and CA.
ID notes: This is a widespread, weedy and highly polymorphic species, frequently confused with the equally common, widespread, and variable C. erythrorhizos and C. strigosus. In addition to the rachilla characters given in the main key, C. strigosus has cormose culm bases (vs. annual with fibrous roots) and spikelets with longer [3.2-4.5 mm vs. (2.0-) 2.2-2.8 (-3.2) mm] scales that are initially quadrangular, becoming strongly compressed at maturity; differences from C. erythrorhizos are discussed under that species.
Origin/Endemic status: Native
Syn: = Va; = Cyperus odoratus – G, GW1, Mi, Pa; > Cyperus ferax – S; > Cyperus ferruginescens – F, RAB; > Cyperus longispicatus – S; > Cyperus macrocephalus – Tx; < Cyperus odoratus – Ar, C, ETx1, FNA23, GrPl, Il, K1, K3, K4, Mo1, NcTx, NE, NY, Tn, W, WH3; > Cyperus odoratus – F, RAB, Tx; > Cyperus odoratus var. odoratus – Tucker & Gandhi (2019); > Cyperus odoratus var. squarrosus – Tucker & Gandhi (2019); > Cyperus speciosus – S; < Torulinum confertum – Bah