Spikes:

1 to 4 hemispheric to oval clusters up to ½ inch across at the tip of the stem, each cluster with 6 to 20 spikelets (flower clusters), occasionally more. The main cluster of spikelets is stalkless, auxiliary clusters are smaller, on stalks up to about ¾ inch long. At the base of the group of clusters are 2 to 4 leaf-like bracts of varying lengths, V-shaped in cross section, the largest about 3 inches long and erect, the others widely spreading. Spikelets are flattened, lance-oblong in outline, up to about 1cm (3/8 inch) long, with 10 to 20 florets, each subtended by a scale. Florets have a single stamen and a 3-parted style. Scales are about 1.5mm long, 7 to 9-veined, the body lance-oblong with a green midrib that extends to an awn about half as long as the body. The scales are arranged overlapping on opposite sides of the central spikelet stalk (rachilla), the awns strongly curved outward (recurved).

Leaves and stems:

Leaves are basal and alternate, typically 1 to 3 per stem near the base, light green when fresh, flat to V-shaped in cross-section, .5 to 2.5mm wide and mostly shorter than the flowering stem. Basal sheaths are purple-tinged to deep purple. Stems are single or multiple from the base, erect to sprawling, 3-sided, smooth and light green. Plants form loose to dense clumps with up to 20 stems in a clump. Dried plants have a pleasant odor when crushed.

Fruit:

The floral scales mature from light green to light brown to deep reddish-brown, the green midrib often turning straw-colored. The scales and achenes (seeds) drop off individually when mature, leaving the naked stalk behind. Achenes are less than 1mm long, light brown to nearly black, 3-sided and somewhat variable in shape but typically rather flat across the top with an abrupt point at the tip, and gradually tapering to the base with short, stalk-like appendage (stipe).

Notes:

Cyperus squarrosus is a common flatsedge with a world-wide distribution. Its form can be variable from a short, dense, compact clump to a taller, lankier plant, possibly depending on environmental conditions. The flowering spikes are initially a light green and look almost fuzzy from the tiny protruding stamens, styles and flaring awns on the scales, then turn a light to deep chestnut brown as spikelets elongate, fruits develop and mature. It is the only Cyperus species in Minnesota known to have awned scales, and the recurved tips make it easy to distinguish from other flatsedges. Most similar is Cyperus acuminatus, which also has one or more globular clusters and spreading tips on the scales, but its scales are not awned and there are often about twice as many spikelets in a cluster as C. squarrosus.