Cyperus diandrus
Cat. Pl. New York, 90. 1819.
Herbs, annual, cespitose, with fibrous roots. Culms trigonous, 4–25(–35) cm, glabrous. Leaves flat, 5–20 cm × 1.5–3 mm. Inflorescences: heads ± digitate, 12–22 mm diam.; rays 3–6, 1–6 cm; bracts 1–4, ± horizontal, flat, 1.5–15 cm × 1.5–3 mm. Spikelets 6–12, oblong-lanceoloid, compressed, 5–10 × 2.8–3.2 mm; floral scales 8–28, closely imbricate, stramineous to light brown or clear (marginal band bright red, spikelet thus appearing dark margined), laterally ribless, oblong to ovate, 2.5–3 × 1.6–1.9 mm. Flowers: stamens 2(–3); anthers 0.3 mm, connective apex reddish, subulate, 0.1–0.2 mm; styles 0.3–0.5 mm; stigmas 2.2–3.1 mm. Achenes brown, network of ridges forming isodiametric or square cells, sessile or stipitate, obovoid to ovoid, 1–1.2 × 0.5–0.6 mm, stipe, if present, 0.1 mm, apex obtuse, apiculate, surfaces minutely punctate.
Phenology: Fruiting summer.
Habitat: Emergent shorelines, in sandy, peaty, or slightly brackish areas (though seldom where disturbed)
Elevation: 0–600 m
Distribution
N.B., N.S., Ont., Que., Conn., Del., Ill., Ind., Iowa, Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., Pa., R.I., Vt., Va.
Discussion
Selected References
None.