| Author | (L.) A. Wood | |
| Distribution | Piedmont, Sandhills, and Coastal Plain, apparently absent from much of the southern Coastal Plain. Not yet known from the Mountains (mapped in Jackson County by BONAP; record needs vetting).
CT to southern OH and KS, south to northern FL, TX, and northeastern Mex. | |
| Abundance | Frequent to common in most of the Piedmont and Coastal Plain; scarce in the Sandhills and the extreme southern Coastal Plain. The State Rank is clearly S5. | |
| Habitat | Dry to mesic open woods, clearings, roadsides, disturbed soils; often in thin and/or sandy soil. | |
| Phenology | Flowering and fruiting July-September. | |
| Identification | Globe Flatsedge is one of the few NC flatsedges to have round or globular flowering heads. In this case the heads are densely packed with spikelets, whereas heads are rather loosely packed in C. croceus. Floral scales of C. croceus are whitish with red speckles (vs. straw colored or brownish in C. echinatus). | |
| Taxonomic Comments | A synonym, often used in older literature, is C. ovularis.
The genus Cyperus is mostly tropical and warm-temperate in distribution; thus, in NC it is much commoner in the Coastal Plain than in the Mountains and Piedmont. Most species have 1-few flowering stems (culms) from grasslike basal leaves, plus a few stem leaves. At the summit is an inflorescence of very open and branched, or tightly packed, spikes, varying among species from brown to golden brown to straw-color to reddish. The arrangement of the spikelets is important, whether like a hand (digitate) or in paired rows (pinnate); as is the shape of the achene (seed), whether bi-convex in cross-section or triangular. As a group, Cyperus tends to be weedy and readily enters disturbed ground; this is true for many natives as well as all the aliens. In recent years, following DNA research, the genus has incorporated several genera that in RAB (1968) or other manuals were separate: Hemicarpha, Lipocarpha, and Kyllinga. | |
| Other Common Name(s) | Roundhead Flatsedge | |
| State Rank | S4 [S5] | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FACU link |
