Spikes:

Separate staminate (male) and pistillate (female) spikes, with a single staminate spike ¼ to 3/8 inch long at the tip of the stem. Below the staminate spike are 2 or 3 pistillate spikes, which are close together and may obscure the staminate spike. Spikes are stalkless or nearly so and green to light brown at flowering time, staminate spikes with creamy yellow stamens, pistillate spikes with long, white, thread-like styles. At the base of lowest spike is a leaf-like bract that is longer than the spike but shorter than the inflorescence (group of spikes).

Leaves and stems:

Leaves are basal and alternate, mostly near the base, 1 to 3.3 mm wide, erect to ascending and mostly shorter than the flowering stem. Stem leaf sheaths are U to V-shaped and translucent whitish-green with vertical veins. The ligule (membrane where the leaf joins the sheath) is wider than long. Leaves are hairless though may be slightly rough.

Bases are wrapped in a red sheath that is not fibrous. Stems are erect to ascending, slender, 3-sided, and mostly smooth. Often only 3 to 5 inches tall at flowering time, the stems elongate up to 18 inches at maturity but more often to about 12 and mostly remain longer than the leaves. Plants form loose clumps and create colonies from spreading rhizomes.

Fruit:

Fruit develops in mid to late spring, the pistillate spikes forming clusters of seeds (achenes), each wrapped in a casing (perigynium), subtended by a scale. The scales of staminate spikes are oval-elliptic, purplish brown with white edging and a blunt or pointed tip. The empty staminate scales persist after fruit has dropped off. Each pistillate spike contains 3 to 10 fruits.

Pistillate scales are 2.2 to 3.2 mm long, 1.2 to 1.8 mm wide, egg-shaped with a pointed tip, whitish green with darker green along the midvein when young, turning brown with maturity, and are ½ to 2/3 as long as the perigynia. Perigynia are 3.2 to 4.2 mm long, 1.1 to 1.5 mm wide, fuzzy hairy, lack veins, turn yellowish at maturity, are generally urn-shaped, the body elliptic, tapering towards the base, and a minute, straight beak that has 2 distinct teeth at the tip. Achenes are 1.3 to 2.3 mm long, .9 to 1.4 mm wide, elliptic, widest at or above the middle, weakly 3-sided in cross-section, and mature to dark brown.

Notes:

Carex peckii is a common sedge primarily found in deciduous woods and mixed deciduous/conifer forest throughout much of Minnesota. It is occasionally found in open sandy or rocky woods and cedar swamps.

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 peckii is in the Acrocystis section (formerly Montanae); some of its common traits are: mostly dry habitat, hairless leaves, basal sheaths typically fibrous, small spikes often tightly clustered, terminal spike staminate, perigynia typically hairy, perigynia with 2 small teeth at the tip of the beak, achenes 3-sided to round in cross-section.

C. peckii is distinguished from other members of Acrocystis by the combination of: a single staminate spike less than 1cm (3/8 inch) long that may be at least partially hidden by the pistillate spikes, pistillate scales half or so as long as the perigynia, hairy perigynia with a body longer than wide, red basal sheaths that are not fibrous, and leaves mostly shorter than the flowering stem.