Carex inops (Sun-loving Sedge)
|Also known as:
|Long-stolon Sedge, Sun Sedge
|sun; dry, sandy soil; prairies, bluffs, barrens, sandy slopes, along railroads
|April - June
|6 to 20 inches
|Wetland Indicator Status:
|MN county distribution (click map to enlarge):
|National distribution (click map to enlarge):
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Separate staminate (male) and pistillate (female) spikes, with a single staminate spike up to about 1 inch long at the tip of the stem. Just below the staminate spike are 1 to 3 pistillate spikes, which are close together or slightly separated. Spikes are stalkless or nearly so and dark purplish brown at flowering time, staminate spikes with showy, creamy yellow stamens, pistillate spikes with long, white, thread-like styles. At the base of a pistillate spike is a scale-like bract that is usually longer than the spike; the lowest spike is typically subtended by a leaf-like bract that is longer than the associated spike but does not over-top the terminal spike.
Leaves and stems:
Leaves are basal and alternate, mostly near the base, .7 to 4.5 mm wide, stiff, mostly erect to ascending and about as long as or shorter than flowering stems at maturity. Stem leaf sheaths are U to V-shaped and translucent whitish-green. Leaves are V-shaped in cross-section and hairless though typically rough-textured. Leaves of vegetative plants are wider than those of flowering plants and may be more arching.
Bases are wrapped in a red sheath that may split with thread-like fibers along the edges, the fibers sometimes connected and forming a ladder pattern. Remnants of leaves from the previous year can persist and may be fibrous. Stems are slender, 3-sided and mostly smooth except near the flowering spikes. Stems can elongate up to 20 inches at maturity. Not all plants produce flowering stems. Plants form loose clumps and create loose colonies from long rhizomes, sometimes in straight lines.
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, the tip blunt or long-tapering to a sharp point. Usually, at least some of the empty staminate scales become spreading, sometimes widely so. Pistillate spikes each contain 5 to 15 fruits.
Pistillate scales are 2.6 to 5.4 mm long, 1.2 to 2.6 mm wide, elliptic to egg-shaped with a pointed tip, the midrib sometimes extending into a short awn, dark purplish brown with a band of white around the edge, and are about as long as the perigynia. Perigynia are 2.8 to 4.6 mm long, 1.5 to 2.2 mm wide, olive green to brown, fuzzy hairy at least in the upper half, lack veins except for 2 ribs, are urn to somewhat spindle-shaped, the body spherical, tapering towards the base, sometimes abruptly so, and an abrupt taper to a straight beak up to 1.3 mm long that has 2 small teeth at the tip. Achenes are 1.6 to 2.5 mm long, 1.5 to 2.2 mm wide, round to oval, nearly round in cross-section, and mature to dark brown.
Carex inops is typically found in open, sandy soils.
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 inops 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.
Carex inops is easily mistaken for Carex pensylvanica and was once considered a variety of it (C. pensylvanica var. digyna, also known as C. heliophila). It is distinguished from C. pensylvanica by the larger perigynia, stiffer leaves, and typical open, sunny habitat, where C. pensylvanica is more often found in woodlands. Note that C. inops is not the only Carex species to form straight lines of plants from its rhizomes; fruiting stems are needed to identify the particular species. There are 2 subspecies of C. inops: subsp. inops is limited to the Pacific coast and has pistillate spikes on short stalks; subsp. heliophila is found east of the Rocky Mountains to Michigan and Indiana, and has stalkless pistillate spikes.
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- Sun-loving Sedge plants
- a line of plants
- a ring of plants
- flowering plant
- staminate spikes with spreading scales
- maturing pistillate spikes
Photos by K. Chayka taken at Hastings Sand Coulee SNA, Dakota County, and Sherburne National Wildlife Refuge, Sherburne County. Photos courtesy Peter M. Dziuk taken at Hastings Sand Coulee SNA.
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