Cyperus esculentus var. macrostachyus

Spikelets divaricate, forming 75-90° angle with rachis, 10-40 × 2.4-3 mm; floral scales ovate, widest at midlength, (2.7-)2.9-3.4(-3.6) × (1.8-)1.9-2.3(-2.4) mm. Flowers: anthers (1.2-)1.3-2(-2.1) mm; styles (0.9-)1.3-2(-2.2) mm; stigmas (2-)2.3-2.8(-4) mm.

Fruiting summer. Dunes, disturbed soils, croplands; 0-200 m; Calif., Fla., Ga., N.Mex., N.Y., N.C., S.C., Tex.; Mexico; Central America; South America.

Perennial herb with slender rhizomes and runners 10 cm - 0.7 m tall Leaves: three to seven, basal, alternate, 20 - 40 cm long, 2 - 8 mm wide, flat or V-shaped in cross-section, linear, parallel-veined, keeled beneath, with a sheathing base that encloses the stem. Inflorescence: consisting of terminal spikes, subtended by spirally arranged leafy bracts. Bracts four to five, more or less horizontal to ascending, unequal, 5 - 30 cm long, 0.5 - 4 mm wide, V-shaped in cross-section. Rays (branches of inflorescence) four to ten, to 12 cm long. Spikes 1.5 - 3 cm long, 1.5 - 3.5 cm long, broadly ellipsoid to egg-shaped or hemispheric, consisting of ten to twenty spikelets. Flowers: minute, in the axil of a floral scale, lacking sepals and petals. Stamens exserted. Anthers to 2 mm long. Pistil one. Style to 2 mm long. Stigma to over 2.5 mm long. Fruit: a one-seeded achene, stalkless, brown, about 1.5 mm long and 0.5 mm wide, oblong with a rounded apex, unequally three-angled, tiny-dotted, often not maturing. Seed with a thin, non-adherent wall. Culm: stout, 10 cm - 0.7 m long, 0.5 - 3.5 mm wide, triangular in cross-section, solid. Spikelets: widely spreading, 1 - 4 cm long, 2.5 - 3 mm wide, linear to linear lance-shaped, compressed four-angled, subtended by two small bracts, with six to thirty-four floral scales. Scales appressed or spreading, brownish or reddish or greenish down the middle, yellowish brown to dark brown along the sides, 3 - 3.5 mm long, 2 - 2.5 mm wide, egg-shaped with a more or less pointed apex, seven- to nine-ribbed, lowest one empty.

Similar species: No information at this time.

Flowering: mid-July to early August

Habitat and ecology: Found in moist, fertile soil, often in cultivated areas.

Occurence in the Chicago region: native

Etymology: Cyperus is the ancient Greek word for sedge. Esculentus means edible.

Author: The Morton Arboretum