| Author | Vahl | |
| Distribution | Throughout the Coastal Plain and lower Piedmont; several records westward but absent from the Mountains.
NJ, PA, and MO south to FL and TX; Mex. south to Ven. | |
| Abundance | Frequent in most of the Coastal Plain and lower Piedmont, but rare to uncommon in the northern Coastal Plain; rare elsewhere. | |
| Habitat | Mesic to moist pinelands, savannas, open woodlands, disturbed areas. | |
| Phenology | Flowering and fruiting July-October. | |
| Identification | The globular heads are usually distinctive, as few other Cyperus have that shape. Cyperus echinatus also has rotund heads, but they are compact and dense (vs. relatively open 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 is C. globosus Boeckeler. In RAB (1968) and elsewhere in the literature, the name C. globulosus Aublet was misapplied to plants of C. croceus.
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 or alternate 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) | Pine-barren Flatsedge, Yellow Flatsedge | |
| State Rank | [S4S5] | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FACU link |
