Carex platyphylla J. Carey

Plants densely cespitose. Culms lateral, ascending, lax, or decumbent, very slender, 14–38 cm × 0.2–0.5 mm. Leaves: basal sheaths white or light brown; sheaths green, lighter to white at base, 1–22 mm; blades erect, ascending, or lax, grayish blue-green, midrib strongly developed, 2 lateral veins developed, 5–22 cm × (7–)11–28 mm, older leaves shriveling or dead at tips. Inflorescences: spikes (2–)3(–4) per culm, scattered; peduncles of pistillate spikes exserted 0–2.2 cm; of staminate spikes 0.1–0.8 cm; bracts from middle and proximal portions of culms 1.4–5.2 cm × 2–6 mm. Pistillate spikes: the proximal basal, erect, 6–16 × 2.8–3.8 mm. Staminate spike 1, linear-clavate, 6–14 × 2–4 mm. Pistillate scales keeled, 3–6 × 1.8–2.2 mm, midribs green, margins hyaline or brown tinged outward, apex apicluate or aristate, awn to 2 mm. Staminate scales obovate, 2.7–5 × 1.8–2.2 mm, midribs green, margins hyaline and brownish to purple tinged outward, apex obtuse to acute. Anthers 3.3–4 mm. Perigynia 2–9 per spike, overlapping, ascending, finely many-veined, obovoid, 3–3.2 × 1.8–2 mm; beak short curved. Achenes ovoid, 2.8–3 × 1.6–1.8 mm, slightly concave at maturity, tightly fitting in perigynia. Style ascending through entire orifice. 2n = 68, 70, n = 32 + (3), 33 + (3), 33 + (4).

N.B., Ont., Que.; Conn., Del., D.C., Ind., Ky., Maine, Md., Mass., Mich., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.

Fruiting spring.

Rich, moist deciduous forests, on rocky or gravelly slopes, soils above limestone, shale, or calcareous metamorphic rocks, often on clay soils; 100–1100m.

Carex platyphylla Carey, Am. Jour. Sci. II. 4: 23. 1847
"Carex plantaginea Lam." Michx. Fl. Bor. Am. 2: 173. 1803. Carex anceps Muhl. var. latifolia Boott, 111. Carex 1: 39, as synonym. 1858. Carex digitalis var. latifolia A. Gray; Boott, 111. Carex 1: 39, as synonym. 1858. Carex platyphylla var. Dudley, Bull. Cornell Univ. 2: 115. 1886. (Type from Cayuga Lake, New York.)
Densely cespitose, the rootstocks very short, the culms lateral, very numerous, slender, erect or ascending or at length decumbent, 15-30 cm. high, asperulous, triangular, not winged, much exceeding the leaves, yellowish-brown at base, the basal sheaths edged with cinnamonbrown ; sterile shoots reduced to tufts of leaves or nearly so ; foliage glaucous, the basal blades and those of the sterile culms 1-2 dm. long, 9-25 mm. wide, flat, thin, but long-persistent, strongly nerved, the midnerve strongly developed on the lower and the two mid-lateral nerves on the upper surface, acute, minutely roughened on the margins, but otherwise very glabrous, prominently reticulate-veined; blades of fertile culms 5 cm. long or less and 5 mm. wide or less, their sheaths 2-5 cm. long, conspicuously white-hyaline ventrally, red-dotted towards the mouth, prolonged upward beyond base of blade and continuous with the long ligule; staminate spike linear-clavate, shortto long-peduncled, 8-15 mm. long, 1.5-2.5 mm. wide, the scales obovate, obtusish or acutish with 3-nerved green center and white-hyaline margins, usually strongly reddish-brown-tinged; pistillate spikes usually 2-4, widely separated, the lower nearly basal, on short, erect, slender, rough peduncles, exserted 1 cm. long or less, or not exserted, linear-oblong, 1-2.5 cm. long, 4-5 mm. wide, loosely and alternately 4—10flowered; bracts leaflet-like, exceeded by the culms, exceeding their own spikes; long-sheathing, the sheaths entire or undulate on the margins, not purple-tinged; scales ovate or obovate, white-hyaline with green midrib, more or less cinnamon-brown-tinged, short-awned, cuspidate, or acuminate, narrower and shorter than the perigynia; perigynia obovoid, appressed-ascending, early deciduous, not at all inflated, sharply triangular, 2.5-3.5 mm. long, 1.75 mm. wide, finely but not conspicuously many-nerved, minutely asperulous, membranaceous, olivegreen, short-stipitate, tapering at base, tapering at apex into a short, erect or slightly excurved beak, with entire hyaline orifice ; achenes broadly oval, sharply triangular with deeply concave sides, closely filling the perigynium, 2.5 mm. long, 1.5 mm. wide, short-stipitate, short-apiculate, jointed with the short, slender, deciduous style; stigmas three, slender, 2.5 mm. long.
Type locality: "Hab. in declivibus umbrosis, Nov. Angl. et Nov. Ebor."
Distribution: Dry open, wooded slopes, Quebec and Ontario, and southward to North Carolina

Carex platyphylla, called the broad leaf sedge and silver sedge, is a species of flowering plant in the genus Carex, native to southeast Canada, and the north-central and eastern United States. It is often found in the same forests as Carex plantaginea, also a broad-leaved species, but they do not compete, as C. plantaginea prefers wet areas and C. platyphylla prefers it dry. Silver sedge is considered a useful native ornamental, since it is showy, deer-resistant, and able to tolerate both deep shade and drought once established.

Carex platyphylla

La Carex à larges feuilles (Carex platyphylla) est une plante nord-américaine de la famille des Cyperaceae.

Carex platyphylla adalah spesies tumbuhan seperti rumput yang tergolong ke dalam famili Cyperaceae. Spesies ini juga merupakan bagian dari ordo Poales. Spesies Carex platyphylla sendiri merupakan bagian dari genus Carex. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh J.Carey.

Carex platyphylla là một loài thực vật có hoa trong họ Cói. Loài này được J.Carey mô tả khoa học đầu tiên năm 1847.