Carex interrupta Boeckeler

Carex interrupta, an uncommon species, is distinguished by the very small, green, glabrous perigynia distended and often split by the developing achenes. Relationships of the species with other members of the section are not clear; it shares distinctive characteristics with C. torta and C. endlichii, the next two species.

Plants not cespitose. Culms obtusely angled, 20–75 cm, glabrous. Leaves: basal sheaths red-brown; sheaths of proximal leaves glabrous, fronts lacking spots and veins, entire, apex U-shaped; blades 3–5 mm wide. Proximal bract subequal to inflorescence, 2–3 mm wide. Spikes erect; proximal 4–7 spikes pistillate, 4–9 cm × 3–4 mm, base attenuate; terminal 1(–2) spikes staminate. Pistillate scales red-brown or black, shorter than or equaling perigynia, apex acute, awnless. Perigynia ascending, olive-green, veinless, distended by and tightly enclosing achenes, ellipsoid or obovoid, 1.5–2.1 × 0.9–1.4 mm, dull, apex rounded, glabrous; beak green, 0.1–0.3 mm, orifice oblique. Achenes not constricted, dull. 2n = 68.

B.C.; Oreg., Wash.

Fruiting Jul–Aug.

Sandy soils along rivers, occasionally wet meadows; 0–600m.

Carex interrupta var. distenta Kükenthal

Carex interrupta Bock. Linnaea 40: 432. 1876
Carex anguslata var. verticillata Boott, in Hook. Fl. Bor. Am. 2: 218. 1839. (Type from Columbia
River.) Carex verticillata Boott, 111. Carex 67. pi. 183, f. 2. 1858. (Based on C. anguslata var. verticillata
Boott. Not C. verticillata Zoll. & Mor. 1846.
Cespitose and stoloniferous, the rootstocks slender but lignescent, brownish, dull, scaly, soon ascending, the culms 2.5-6 dm. high, slender, erect, papillate, exceeding the leaves, smooth to strongly roughened above, purplish-red-tinged at base, obscurely phyllopodic, the dried-up leaves of the previous year not conspicuous; sterile shoots aphyllopodic; leaves of the flowering year with well-developed blades 3-5 to a fertile culm, on the lower third or half, usually more or less clustered, the upper the longer, the lower much reduced, obscurely septatenodulose, the blades flat, with margins revolute above, thin, usually 5-20 cm. long, 3-5 mm. wide, short-tapering, light-green, papillate, roughened towards apex ; the sheaths rounded and smooth dorsally, very membranaceous and quickly breaking ventrally but not filamentose, dull-whitish or yellowish-brown-tinged, the ligule as long as wide; staminate spike solitary, more or less strongly peduncled, linear, 1.5-4 cm. long, 4-5 mm. wide, the scales oblongobovate, obtuse, reddish-purple with lighter center and narrow hyaline margins; pistillate spikes 3-5, erect, more or less strongly separate, occasionally staminate at apex, the upper 1-3 cm. long, short-linear or oblong-linear, sessile or nearly so, densely flowered to the base, the lower one or two 4-9 cm. long, elongate-linear, strongly peduncled and usually very loosely flowered at the base, 3-5 mm. wide, containing 30-100 appressed-ascending perigynia in few to several rows; lowest bract leaf-like, shorter than culm, not sheathing, the auricles often darkened; upper bracts very much reduced, the uppermost scale-like; scales ovate or ovatelanceolate, acute or obtusish, much narrower than and from slightly shorter to slightly longer than perigynia, reddish-purple with lighter center and very narrow hyaline margins; perigynia very small, suborbicular or short-oval, much flattened and 2-edged, 2-ribbed (the marginal), otherwise nerveless, 1.5-2 mm. long, 1-1.25 mm. wide, green or at maturity olive-green, smooth, or very sparingly scabrous on margins above, puncticulate, sessile, rounded at base and apex, very abruptly and very minutely short-beaked, the beak emarginate or minutely bidentate, 0.1-0.2 mm. long; achenes lenticular, suborbicular, nearly filling body of perigynium, sessile, 1.25 mm. long and about as wide, minutely apiculate, jointed with the very short style; stigmas 2, slender.
Type locality (of C. angustata var. verticillata Boott, on which C. interrupta is based): "Columbia River; Scolder. Oregon, NiUtall."
Distribution: Swampy meadows along streams, Oregon and Washington. A rare and local species. (Specimens examined from Oregon, Washington.)

Carex interrupta is a tussock-forming species of perennial sedge in the family Cyperaceae. It is native to south eastern parts of Canada and north eastern parts of the United States.

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

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

Carex interrupta là một loài thực vật có hoa trong họ Cói. Loài này được Boeckeler mô tả khoa học đầu tiên năm 1876.