Cyperus esculentus var. heermannii
Bull. Torrey Bot. Club 13: 211. 1886.
Spikelets ascending-erect, forming less than 40° angle with rachis, closely spaced (2 or more per mm of rachis), 15–25(–55) mm; floral scales deltate-ovate, widest at 1/4–1/3 length, 2.4–2.6 × 1.7–1.8 mm. Flowers: anthers 1.2 mm; styles 0.9 mm; stigmas 1.6 mm.
Phenology: Fruiting summer.
Habitat: Disturbed soils, croplands
Elevation: 0–1200 m
Calif., Fla., Utah, Mexico.
Cyperus esculentus var. heermannii is the least common and most geographically restricted of the varieties. Its spikes are more dense (2 or more spikelets per mm of rachis) than the other varieties (ca. 1 spikelet per mm of rachis).