Kyllinga resembles Cyperus but has extremely flat spikes with 2-3 scales (vs. 5 or more scales in Cyperus).
1. Spikelets dome-shaped, not taller than broad...K. brevifolia (plants creeping)
1. Spikelets cylindric or thimble-shaped...2
2. Perennial. Spikelets white, slightly fragrant. Achenes white basally...K. odorata (plants cespitose or rhizomatous, and see note below concerning K. squamulata)
2. Annual. Spikes green. Achenes green...K. pumila
Note: Kyllinga squamulata Vahl is an introduced Asian species widespread in Florida and could readily turn up in our area. It resembles the native K. odorata by having cylindric thimble-shaped spikelets but is unique among our species by having a lacerate wing on the central nerve of the scales. Microscopic image of this detail below.