Cyperus retrofractus (Linnaeus) Torrey. Rough Flatsedge. Phen: Jul-Sep. Hab: Dry sandy or rocky woodlands and fields. Dist: NJ west to s. OH, and se. MO, south to GA. AL, and AR.

ID notes:C. lancastriensis is occasionally confused with this species, which, unlike other members of the C. retrofractus complex, often has multiple fertile scales; C. lancastriensis has spikelets reflexed only in the proximal half of the spike, lacking prolonged, involute terminal scales, and oblong-falcate (vs. narrowly oblong and straight) achenes.

Origin/Endemic status: Native

Taxonomy Comments: See Carter and Jarvis (1986) for clarification of nomenclature.

Synonymy: = Ar, C, FNA23, K1, K3, K4, Mo1, Pa, Tn, Tx, Va, WH3; = Cyperus dipsaciformis Fernald – F, RAB, S, Tat, W; = Cyperus retrofractus (L.) Torr. var. dipsaciformis (Fernald) Kük. – G

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Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: FACU (taxonomic split from wetland indicator species)
• Eastern Mountains and Piedmont: UPL (taxonomic split from wetland indicator species)
• Great Plains: UPL (taxonomic split from wetland indicator species)
• Midwest: UPL (taxonomic split from wetland indicator species)
• Northcentral & Northeast: UPL (taxonomic split from wetland indicator species)

Heliophily: 8