Carex amphibola Steud.

The wide-ranging, habitat generalist Carex amphibola is the most common member of Carex sect. Griseae. It grows with many other members of the section, most often C. bulbostylis, C. corrugata, C. glaucodea, C. grisea, C. oligocarpa, and C. planispicata.

Plants densely cespitose; rhizo1me internodes 1.2–2 mm thick. Culms dark purple-red to 0.3–2.4(–7.3) cm high or very rarely brown at base, 15–80 cm. Leaves: sheaths glabrous; blades green, widest blades (3.7–)4.4–7 mm wide, smooth abaxially. Inflorescences 0.48–0.93 of culm height; peduncles of lateral spikes glabrous or barely scaberulous; peduncles of terminal spikes 1.6–21(–37) mm, usually barely exceeding lateral spikes; proximal bract sheaths loose, glabrous abaxially, sheath front slightly concave to slightly convex, elongated 0.6–2.2(–5) mm beyond apex; ligules (1.8–)3.4–7.8(–12.9) mm; distal bract much exceeding terminal spike. Spike (3–) 4–5, distal 2–4 overlapping; lateral spikes pistillate, with 3–18 perigynia, 5–26 × 4.6–9.8 mm, ratio of spike length (in mm) to flower number = 1.3–1.9; terminal spikes 7–34 × 1.1–2.7 mm. Pistillate scales 3.7–8 × 1.2–2.4 mm, margins whitish and usually with red-brown speckles, entire, apex with awn 1.1–6 mm. Staminate scales 3.6–4.9 × 1.1–1.9 mm. Anthers 2–2.8 mm. Perigynia spirally imbricate, 52–64-veined, unwrinkled to wrinkled, oblong-lanceoloid to narrowly oblong-ovoid, obtusely triangular in cross section, 4.2–5(–5.2) × 1.5–1.9(–2.2) mm, (2.2–)2.5–3.1 times as long as wide, lustrous, base very gradually tapered, apex gradually tapered; beak absent or straight, 0–0.2 mm. Achenes broadly obovoid to oblong-obovoid, widest at 0.55–0.67(–0.7) of body length, (2.6–)2.8–3.4 × (1.3–)1.5–1.7(–1.8) mm, loosely enveloped by perigynia; stipe straight, (0.3–)0.4–0.6 mm; beak straight, 0.3–0.6 mm.

Ont.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Ky., La., Md., Mass., Mich., Miss., Mo., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.

Fruiting spring–early summer.

Mesic deciduous forests; usually in acidic loams on flood plains, slopes above streams, and uplands; 10–1000m.

Carex grisea Wahlenberg var. amphibola (Steudel) Kükenthal

Carex amphibola Steud. Syn. Cyp. 234. 1855
Carex grisea var. anguslifolia Boott, 111. Carex 34. pi. 87. 1858. (Type from Texas.)
Carex cryptandra Schw.; E. Hall, PI. Tex. 25, name only. 1873.
Carex cryptandra var. peduncidata Olney; E. Hall, PI. Tex. 25, name only. 1873.
Carex grisea var. minor Olney; E. Hall, PI. Tex. 25, name only. 1873. (Type from Texas.)
Carex grisea var. minor Bock. Linnaea 40: 443. 1876. (Based on C. grisea var. angustifolia Boott and Texas plant cited.)
Carex grisea var. (?) rigida L. H. Bailey, Mem. Torrey Club 1: 56. 1889. (Type from Sellersville, Pennsylvania.)
Carex grisea var. amphibola Kukenth. in Engler, Pflanzenreich 4 20 : 520. 1909. (Based on C. amphibola Steud.)
Densely cespitose, the rootstocks very short, the culms very slender but erect, lateral or central, 2-6 dm. high, leafy throughout, triangular, smooth or nearly so, exceeded by the leaves, strongly purple-tinged at base; sterile shoots elongate, conspicuous; leaves with blades 1-3 dm. long, and 2-4 mm. wide, erect, thin, flat, deep-green, long-attenuate, the midvein prominent on the lower surface and the two mid-lateral veins on the upper, roughened towards the apex, the sheaths white-hyaline ventrally and somewhat yellowish-brown-tinged and reddotted, the ligule conspicuous, longer than wide; staminate spike slender, rough-peduncled, linear, 1-3 cm. long, 1.5-2.5 mm. wide, the scales oblong-obovate, obtuse or acutish, whitishhyaline with 3-nerved green center, reddish-brown-tinged; pistillate spikes 3-5, linear-oblong, 1-2.5 cm. long, 2.5-4 mm. wide, widely and evenly separate, the lowest nearly basal, erect on slender, smooth, more or less strongly exserted peduncles, with 4-12 erect-ascending perigynia somewhat alternate in few rows; bracts long-sheathing, the sheaths smooth, tight, long-bladed, the upper overlapping the culms; scales ovate-triangular, much narrower and shorter than the perigynia, strongly awned, white-hyaline with green midvein, slightly yellowish-brown-tinged and red-dotted ; perigynia oblong-oval, suborbicular-triangular in cross-section, not or scarcely turgid, 3.5-4.5 mm. long, 2 mm. wide, minutely asperulous and puncticulate, subcoriaceous, light-green or in age yellowish-brown, finely impressed with many nerves, sessile, rounded at base, very minutely short-pointed at apex, the orifice slightly hyaline, entire ; achenes obovoid, 2.5 mm. long, 1.5 mm. wide, triangular with concave sides, somewhat loosely enveloped in lower three-fourths of perigynium, yellowish-brown, granular, slenderly short-stipitate, apiculate, jointed with the straight slender style; stigmas 3, reddish-brown, slender, 2 mm. long.
Type locality: "Carex nr. 437. Drummond. * * * Am. sptr."
Distribution: Dry woodlands, Florida and Texas northward to western New Jersey, and in the interior to Indiana. (Specimens examined from western New Jersey, Pennsylvania, Delaware, Maryland, District of Columbia, South Carolina, Georgia, Florida, Alabama, Mississippi, Texas, Arkansas, Missouri, Kentucky, Indiana.)

Carex amphibola, known as gray sedge, is a species of flowering plant in the family Cyperaceae. It was first formally named in 1855. Carex amphibola is native to the eastern United States and Canada.

Carex amphibola is commonly confused with Carex grisea, which has somewhat greener perigynia with more rounded tips, versus the gray-green coloring and angular tips of C. amphibola perigynia. The perigynia of C. amphibola are somewhat more clustered and spreading at maturity, while those of C. grisea are strongly ascending.

Carex amphibola grows in mesic deciduous forests, often in loamy areas near streams.

Carex amphibola est une espèce de plantes du genre Carex et de la famille des Cyperaceae.

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

Carex amphibola là một loài thực vật có hoa trong họ Cói. Loài này được Steud. mô tả khoa học đầu tiên năm 1855.