Northern Ontario Plant Database

Carex Reproductive Structures: Sedge flowers are unisexual and arranged in spikes, also called heads. Male and female flowers may be arranged on separate spikes or with flowers of one sex clustered at the top of the spike, subtended by flowers of the opposite sex. Sepals and petals are lacking. Female flowers consist of a superior ovary with one style terminating in 2 or 3 stigmas; the ovary is surrounded by a persistent sac-like bract called a perigynium. The mature perigynium is often topped by a beak, which represents the remains of the persistent style base. The beak varies, according to species, from long and tapering, with 2 small teeth at the tip, to blunt and toothless. The ovaries of Carex species with 2 stigmas produce flattened, 2-angled, indehiscent fruits (lenticular achenes), while those species with 3 stigmas produce 3-angled fruits (trigonous achenes). In female spikes, the flowers are each subtended by a bract, called a pistillate scale. In male spikes, with flowers consisting of only 1–3 stamens, the subtending bract is called a staminate scale.

General: Sedges are herbaceous plants with simple, linear or bladeless leaves; stems are solid and usually 3-angled in cross section; leaves are arranged in 3 rows (3-ranked) along the stem. The leaves and stems of Carex lucorum are smooth or only slightly rough-textured (scabrous); plants grow in dense leafy tufts, with reddish bases; plants spread by slender, leafless stolons; flowering stems grow to 4 dm tall.

Leaves: Basal, linear, 1–3 mm wide, relatively soft.

Spikes: The terminal spike is staminate, to 2 cm long, subtended by 1–4 rounded or ovoid, sessile, pistillate spikes, 3–12 mm long. The lowest spike is subtended by a leafy bract.

Perigynia: Ovoid, pubescent, obtusely 3-angled, 3–4 mm long, with a slender beak 2/3 as long as, or about equal to the length of, the perigynium; the beak bears 2 terminal teeth. Pistillate scales are ovate to lanceolate, reddish-purple or brown, about equal in length to the perigynium. Flowers open in the spring.

Habitat and Range: Dry wood, thickets, sandy or acidic soils, especially in oak or pine stands. Carex lucorum is native to northeastern North America. In Ontario, this species is represented by var. lucorum; Scoggan (1978) reports it only from southern Ontario.

Internet Images: This illustration of Carex lucorum website. Click on each illustration for a larger image.

See also this image of Carex lucorum

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