Flower:

2 to 6 clusters up to ½ inch long at the tip of the stem, each cluster with 3 to 8 spikelets (flower clusters), usually 5 or less. The main cluster of spikelets is stalkless and hemispheric in outline, auxiliary clusters are on stalks ½ to about 3 inches long, with spikelets arranged widely spreading to ascending and the terminal spikelet usually erect. At the base of the group of clusters are 2 or 3 ascending to spreading leaf-like bracts, the largest up to about 4 inches long and nearly erect.

Spikelets are flattened, linear-oblong in outline, up to 18mm (.7 inch) long, with 8 to 30 florets, each subtended by a scale. Florets have 2 or 3 stamens and a 2-parted style. Scales are 1.9 to 2.7mm long, lance-oval, blunt at the tip, rather shiny, reddish-brown to maroon at the base, often all the way to the edge except green at the tip end, 3-ribbed with a green midrib. The scales are arranged ascending and tightly packed, overlapping on opposite sides of the central spikelet stalk (rachilla).

Leaves and stems:

Leaves are basal and alternate, typically 1 to 3 per stem near the base, V-shaped in cross-section, 1 to 2mm wide, mostly shorter than the flowering stem, and green to olive green. Basal sheaths are brown to reddish-brown. Stems are multiple from the base, erect to prostrate, 3-sided and smooth. Plants form loose to dense clumps and often form dense colonies.

Fruit:

The floral scales and achenes (seeds) drop off individually when mature, leaving the naked stalk behind. Achenes are 1 to 1.5mm long, brown to blackish, lens-shaped and generally oval in outline.

Notes:

Cyperus bipartitus is one of the more common flatsedges in Minnesota, found along lake and pond shores, wet meadows, and other low, seasonally wet areas. It is easily confused with Cyperus diandrus, which has clusters usually with 6 or more spikelets, floral scales that are maroon to reddish-brown along the edges, especially at the tip end, and long, persistent styles (see comparison photo below).