Spikes:

Separate staminate (male) and pistillate (female) spikes, with a single staminate spike about ½ inch long at the top of the stem, which occasionally has a few to several pistillate flowers at the very tip (gynecandrous) or near the middle. Below the staminate spike are 2 to 5 pistillate spikes which are either all-pistillate or more often have a few staminate flowers at the very tip (androgynous). The lowest spike may be widely separated from the spike above it, and is typically stalked; the uppermost spikes are stalkless or nearly so and more closely crowded. At the base of each pistillate spike is a leaf-like bract that is up to 4 times as long as the inflorescence (group of spikes) and over-tops the terminal spike. Pistillate spikes are stout, round to elliptic in outline, 1/3 to ¾ inch long, erect to ascending, green at flowering time with white, thread-like styles, the staminate flowers with creamy yellow stamens.

Leaves and stems:

Leaves are basal and alternate, mostly near the base, 1.5 to 3.1(4.5) mm wide, mostly shorter than the flowering stems. Stem leaf sheaths are membranous on the front side and U-shaped at the tip. The ligule (membrane where the leaf joins the sheath) are mostly longer than wide, though on uppermost leaves may be straight or convex. Leaves are hairless though slightly rough along the edges.

Bases are wrapped in a light tan to green sheath that is not fibrous. Stems are slender, 3-sided, mostly smooth, elongating up to 20 inches at maturity and are mostly longer than the leaves. Not all plants produce flowering stems. Plants can form dense clumps from short rhizomes.

Fruit:

Fruit develops in late spring through mid-summer, the pistillate spikes forming clusters of seeds (achenes), each wrapped in a casing (perigynium), subtended by a scale. The empty staminate scales persist after fruit has dropped off. Pistillate spikes each contain up to 35 fruits that are tightly crowded on the stalk, widely spreading or those towards the base of the spike angled down (reflexed).

Pistillate scales are lance-oblong with a pointed tip, pale green to yellowish or only slightly tinged brown, shorter than the perigynia, and inconspicuous against the similarly colored perigynia. Perigynia are 3.2 to 4.5 mm long, 1.1 to 1.7 mm wide, hairless, yellowish green at maturity, 8 to 20 nerved (best seen when dry), loosely wrapping the achene, somewhat irregular in shape but widest above the middle, tapering to a beak about as long as the body, the beak smooth, distinctly angled and with 2 teeth at the tip. Achenes are 1.2 to 1.5 mm long, up to 1.2 mm wide, 3-sided in cross-section, and mature to dark brown.

Notes:

Carex cryptolepis is found in peaty or sandy wetlands in the Anoka Sandplain and into north central and northeast Minnesota.

Carex is a large genus, with over 600 species in North America and 150+ in Minnesota alone. They are grouped into sections, the species in each group having common traits. Carex cryptolepis is in the Ceratocystis section; some of its common traits are: typically clump forming, leaves hairless, leaves V-shaped in cross-section when young, spikes short and stout, terminal spike either all staminate or with a few perigynia, perigynia tightly crowded on the spike, spreading to reflexed, round in cross-section, beaked, the beak usually toothed, 3-sided achenes.

Carex cryptolepis is very similar in appearance to two other Minnesota sedges: Carex flava and Carex viridula. C. cryptolepis is distinguished by the pistillate scales having a similar color as the perigynia and often hidden altogether at maturity, perigynia at the base of a spike reflexed, and smooth beaks about as long as the body and distinctly angled. By contrast, C. flava pistillate scales are distinctly tinged brown to reddish and conspicuous, its perigynia are larger (4 to 6.3 mm), and beaks are rough textured. C. viridula perigynia are mostly spreading, not reflexed, somewhat smaller (to 3.5 mm long) and beaks are shorter and mostly straight or only slightly angled.