Carex macrochaeta C. A. Mey.

T. V. Egorova (1999) included Carex macrochaeta in sect. Scitae. The species commonly has a white or cream tomentum on many roots, although most individuals have at least some roots with a yellowish tomentum. The sectional placement of this species requires further investigation.

Culms aphyllopodic, without dead leaf remains at base, 20–70 cm. Leaf blades 2–5 mm wide, margins revolute, scabrous at tip. Inflorescences: proximal bracts 4–11 cm, shorter to longer than inflorescences; lateral spikes 10–30 × 6–8 mm, with 15–40 perigynia; terminal spikes 12–32 × 3–8 mm. Pistillate scales lanceolate, 3–7.5(–9) × 1.6–2.5 mm, narrower that, longer than perigynia, awn to 2–12 mm. Staminate scales oblong-obovate, 4.5–6 × 1.3–2.4 mm, apex bifid to emarginate, at least proximal scales with awn 2–6 mm. Anthers 3.3–5 mm. Perigynia 3.8–6.8 × 1.7–2.3 mm, apex tapering and rounded; beak 0.1–0.3 mm. 2n = 60.

B.C., Yukon; Alaska, Oreg., Wash.; coastal Asia.

Fruiting summer.

Marshes, shores, and other wet open places; 0–1000m.

Carex macrochaeta C. Meyer, Mem. Acad. St.-Petersb Sav. Etr. 1: 224. pi. 13. 1831.
Carex excurrens Cham.; Steud. Syn. Cyp. 228, as synonym. 1855.
"Carex podocarpa R. Br." Dewey, Am. Jour. Sci. 29: 251. pi. Z, f. 83. 1836; Boott, 111. Carex 4:
197, in part. 1867. (Plants from northwestern America.) Carex macrochaela var. emarginala Holm, Am. Jour. Sci. IV. 17: 314. 1904. (Type from Kukak
Bay, Alaska.) Carex macrochaela var. macrochlaena Holm, Am. Jour. Sci. IV. 17: 315. 1904. (Type from St.
Paul Island, Rcring Sea.) Carex Kuhleweinii Gand. Bull. Soc. Bot. Fr. 66: 295. 1920. (Type from Sitka, Alaska.)
Loosely cespitose in medium-sized clumps from densely matted, tough, scaly rootstalks, the culms 2-6 dm. high, slender, erect, or nodding at apex, sharply triangular, more or less strongly exceeding the leaves, smooth or slightly roughened above, aphyllopodic, strongly purplish-red-tinged and fibrillose at base; leaves with well-developed blades 2-5 to a fertile culm, on the lower third or half, but not clustered, light-green, firm, the blades flat with revolute margins, 0.3-2 dm. long, 2-5 mm. wide, somewhat roughened towards the blunt-tipped apex; sterile culm-blades longer, 1.5-3 dm. long, long-attenuate, sheaths yellowish-browntinged ventrally, concave at mouth, strongly prolonged beyond base of blade, the ligule as long as wide; staminate spike usually solitary, peduncled, oblong-linear or narrowly oblong, 1.5-2.5 cm. long, 4-8 mm. wide, the scales oblong-obovate, blackish with minutely hyaline edge and conspicuous light-colored midrib strongly exserted at the bifid or emarginate apex as a slender rough cusp; anthers very conspicuous, 5 mm. long; pistillate spikes 2-4, more or less strongly separate, the upper erect and short-peduncled or nearly sessile, the lower varying from short-peduncled and erect to strongly (2-4 cm.) peduncled and drooping, the peduncles slender, smooth, the spikes oblong or oblong-cylindric, 1-3 cm. long, 6-8 mm. wide (without awns), closely flowered, containing 15-40 closely appressed perigynia in several rows; lower bract leaflet-like, shorter than or exceeding inflorescence, not sheathing, often dark-auricled; upper bracts reduced; scales ovate-oblong, black with slightly hyaline margins and whitish midrib, the midrib excurrent as a very slender rough cusp 2-12 mm. long from the emarginate or bifid apex, the scales slightly narrower and shorter than the perigynia; perigynia oblongovate or oblong-oval, much compressed, thin, 4.5-6 mm. long, 2 mm. wide, thin, membranaceous, minutely papillate, straw-colored, occasionally dark-blotched, obscurely slenderly nerved, substipitate, rounded at base and round-tapering at apex, abruptly very minutely (0.2 mm.) beaked, the orifice purplish, entire or very obscurely emarginate; achenes oblongobovoid, 2-2.5 mm. long, 1-1.25 mm. wide, loosely enveloped in lower half of perigynium, triangular with sides concave below, short-stipitate, brownish, apiculate, jointed with the nearly straight, slender style; stigmas 3, reddish-brown, thickish towards base.
Type locality: "Habitat in Unalaschka."
Distribution: Wet open places, Multnomah Falls, Oregon, northward along the coast mostly west of the mountains to the Aleutian and Pribilof Islands and southward on the Asiatic coast to Sakhalin; locally in the interior. A handsome plant and one of the most characteristic species of the Alaskan coast. (Specimens examined from Vancouver, Yukon, Alaska.)

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

Carex macrochaeta là một loài thực vật có hoa trong họ Cói. Loài này được C.A.Mey. mô tả khoa học đầu tiên năm 1831.