Lesser Black Scale Sedge

The absence of collections of Carex atrosquama in Wyoming is unexpected.

Plants loosely cespitose. Culms 20–50 cm, distally scabrous. Leaves 3–5 mm wide. Inflorescences: proximal bracts shorter than or exceeding inflorescences; spikes contiguous or the proximal separate, overlapping, erect, distinct, short-pendunculate, short-oblong or elongate, 8–20 × 5–6 mm; lateral 2–3(–5) spikes pistillate, of similar length; terminal spike gynecandrous. Pistillate scales dark brown or black to margins, ovate or broadly lanceolate, shorter than and as broad as perigynia, midvein same color as body, inconspicuous, occasionally raised, prominent, short-mucronate. Perigynia ascending, pale green becoming golden brown, veinless, elliptic, 2.5–3.5 × 1.5–1.75 mm, apex gradually or abruptly beaked, distally papillose; beak 0.3–0.5 mm, entire or shallowly bidentate, smooth. Achenes nearly filling body of perigynia.

Alta., B.C., N.W.T., Yukon; Alaska, Colo., Idaho, Mont., Oreg., Utah, Wash.

Fruiting Jun–Aug.

Subalpine and alpine meadows, river gravels, shorelines; 300–3600m.

Carex apoda Clokey; C. atrata Linnaeus subsp. atrosquama (Mackenzie) Hultén; C. atrata var. atrosquama (Mackenzie) Cronquist

Carex atrosquama Mackenzie, Proc. Biol. Soc. Wash 25:51. 1912.
Carex apoda Clokey, Am. Jour. Sci. V. 3 : 88. pi. 2,f. 1-6. 1922. (Type from Custer County, Idaho.)
Densely cespitose, the rootstocks very short, slender, the culms 1.5-5 dm. high, slender, erect, or at maturity nodding, sharply triangular, slightly roughened above, much exceeding the leaves, phyllopodic, dark-purplish-red-tinged at base, the lower sheaths sparingly filamentose, the dried-up leaves of the previous year conspicuous; leaves with well-developed blades 7-10 to a fertile culm, on lower fourth, mostly clustered near base, the blades deep-green, firm, flat, with slightly revolute margins, 0.5-2.5 dm. long, 1.5-3.5 mm. wide, mostly erect, attenuate, roughened towards the apex, the sheaths whitish or yellowish-white ventrally, concave at mouth, the ligule as long as wide; spikes 3 or 4, the lateral pistillate, the terminal gynaecandrous and clavate at base, approximate or the lower slightly separate, the lower 1 or 2 on erect peduncles half to twice their own length, the others sessile or nearly so, the peduncles rough, triangular, the spikes oblong, 6-20 mm. long, 5-6 mm. wide, densely 15-35flowered, with appressed perigynia in several rows; lowest bract leaflet-like, slightly or not at all sheathing, not or but little purplish-tinged, shorter than or exceeding the inflorescence; upper bracts much reduced ; scales broadly ovate, obtuse or slightly acute, black, the midvein obsolete or very indistinct, and the upper margins not at all or but very slightly hyaline, nearly the width of but markedly shorter than the perigynia; perigynia narrowly ellipticobovoid, 3.25 mm. long, 1.75 mm. wide, nerveless, granular-roughened above, puncticulate, olive-green, becoming yellowish-brown, sometimes slightly purplish-spotted, membranaceous, slightly inflated, suborbicular and but little flattened at maturity, glabrous, sessile, roundtapering at base, abruptly contracted into a minute shallowly bidentate purplish-black beak 0.5 mm. long; achenes obovoid, 1.5-2 mm. long, 1 mm. wide, rather loosely enveloped in lower part of body of perigynium, triangular with sides somewhat concave below, stipitate, dull-yellowish-brown, slightly granular, apiculate, jointed with the slender, not exserted style ; stigmas 3, short, slender, whitish at flowering.
Type locality: Head of Smoky River, Alberta (N. Hollister 14).
Distribution: Mountain meadows, Alberta to British Columbia, and southward to Montana, Idaho and Oregon. (Specimens examined from Alberta, British Columbia, Montana, Idaho, and Oregon.)

Carex atrosquama, the lesser blackscale sedge, is a species of sedge that was first formally named by Kenneth Mackenzie in 1912. It is native to the northwestern United States and western Canada, from Alaska south to Utah and Colorado. It grows in alpine and subalpine meadows, as well as along rivers and streams in gravelly areas.