Triangularfruit Sedge

Culms 30–75 cm, ± smooth. Leaf blades 2–4 mm wide, margins revolute. Spikes: lateral spikes all in distal 1/2 of stem, 10–45 × 4–7 mm; terminal spikes 10–35 × 2–4 mm. Pistillate scales 3-veined, ovate to ovate-circular, 3.7–5 × 2–2.6 mm, proximal ones shorter than perigynia. Perigynia 3.7–4.5 × 2–2.5. Achenes sessile, 3.3–3.5 × 1.9–2.5 mm.

Calif.; Mexico (Baja California).

Fruiting late spring.

Dry grasslands and scrub; of conservation concern; 0–600m.

Carex triquetra Boott, Trans. Linn. Soc. 20: 126. 1846
Carex monticola Dewey, in Torr. Bot. Mex. Boimd. Surv. 229. 1859. (Type from San Diego County, California.)
Cespitose and not stoloniferous, the clumps rather large, the culms 3-6 dm. high, slender but stiff, sharply triangular, smooth or somewhat roughened above, exceeding the leaves, phyllopodic, cinnamon-brown-tinged at base; leaves with well-developed blades usually 3-6 to a fertile culm, on the lower half, but not bunched, not septate nodulose, the blades usually 1-2 dm. long, 2.5-6 mm. wide, glabrous, densely papillose, light-green, rigid, flat with revolute margins, the sheaths cinnamon-brown-tinged ventrally and strongly purple-dotted, tight, concave at mouth, the ligule wider than long; terminal spike linear-subclavate, staminate, erect, short-peduncled to nearly sessile, 1-3 cm. long, 2-4 mm. wide, the scales appressed, ovate, obtuse to acutish, reddish-brown with hyaline margins and 3-ribbed, often greenish, center; pistillate spikes usually 3, often with a few staminate flowers at the apex, the uppermost close to the staminate, the second moderately separate, the third much separate (usually near the middle of the culm), the spikes from short to linear-oblong, 1-4.5 cm. long, 4-7 mm. wide, the upper sessile or short-peduncled, erect, the lowermost on slender, often greatly elongate peduncles, the 5-30 perigynia in few rows, ascending, rather closely disposed and overlapping; bracts mostly shorter than inflorescence, the lowermost well-developed and leaflike with ver long sheath, the upper shorter but with well-developed sheaths; scales broadly ovate, sharply keeled, short-cuspidate to acute, about the width of but shorter than the mature perigynia, copper-red with very narrow hyaline margins and 3-ribbed green center; perigynia broadly ovoid or obovoid, sharply triangular, membranaceous, grayish-green, 4-4.5 mm. long, 2.75 mm. wide, short -pubescent, obscurely nerved on the sides, (nearly nerveless at maturity), sessile, round-tapering at base, very abruptly and bluntly narrowed at apex into a very short beak about 0.3 mm. long, minutely bidentate; achenes sharply triangular with concave sides, closely enveloped, densely puncticulate, sessile, obovoid, 3.5 mm. long, 2.5 mm. wide, short-apiculate, jointed w-ith the very short, thickish style; stigmas three, slender, reddishbrown.
Type locality: "Hab. in California. Nutlall." (More specifically, Santa Barbara, as written by Boott in his own copy of his original description in my possession.)
Distribution; Dry hillsides below 600 meters altitude, in southwestern California from Santa Barbara County south, and extending into northern Lower California. (Specimens examined from southwestern California, and northern Lower California.)

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

Carex triquetra là một loài thực vật có hoa trong họ Cói. Loài này được Boott mô tả khoa học đầu tiên năm 1851.