Cyperus thyrsiflorus Junghuhn. Southern Flatsedge. Phen: May-Sep. Hab: Calcareous woodlands/hammocks, swamp edges, and shell middens. Dist: E. SC south to s. FL, west to se. TX; West Indies; South America.
ID notes: C. pseudothyrsiflorus is sometimes confused with this species. C. pseudothyrsiflorus is a more robust plant, with mucronate scales, maturing reddish-brown (vs. pale olivaceous); see Key ZD. C. tenuis, a Central American species, has been reported from southern Texas, probably based on material of this species; it has much denser ovoid (vs. oblong-cylindric, parallel-sided) spikes, slightly flattened spikelets, and greenish scales overlapping at least 1/4-1/3 of the next distal scale.
Origin/Endemic status: Native
Syn: = ETx1, FNA23, K1, K3, K4, WH3, Carter & Jones (1997); = Cyperus hermaphroditus – S, misapplied