Baikal Sedge

Carex sabulosa was first recognized in North America as C. leiophylla Mackenzie. M. Raymond (1965) reported their similarity and considered C. sabulosa and C. leiophylla synonymous. A. E. Porsild (1966), on the other hand, saw distinctions, hence the combination C. sabulosa subsp. leiophylla. Our material falls well within the variation of C. sabulosa from Asia. The nearest extraterritorial locality is on the lower Lena River, Yakutia (Sakha).

Plants cespitose, long-creeping rhizomatous. Culms 25–35 cm, smooth. Leaves 2–3 mm wide, often circinate. Inflorescences: proximal bracts shorter than or exceeding inflorescences; spikes globose or elongate, 6–17 × 6–10 mm; proximal spikes sometimes erect, separate, short-pedunculate; distal spikes contiguous, overlapping, or erect, sessile or short-pendunculate, forming dense terminal cluster; lateral 1–2(–4) spikes pistillate; terminal spike gynecandrous. Pistillate scales light to dark brown or chestnut, distal margins broadly hyaline, lanceolate, equaling or, more commonly, exceeding and narrower than perigynia, midvein lighter colored than body, conspicuous, often raised, prominent, apex acute or mucronate. Perigynia ascending, light brown, strongly veined, broadly elliptic, 4–5 × 2–3 mm, apex abruptly beaked, smooth or distally papillose; beak 0.6–0.8 mm, deeply, sharply bidentate, smooth or papillose. Achenes nearly filling body of perigynia.

Yukon; Alaska; Asia (Kazakhstan, Mongolia, Russia).

Fruiting Jun–Aug.

Riverine sand exposures, dune fields; 600–800m.

Carex leiophylla Mackenzie; C. sabulosa subsp. leiophylla (Mackenzie) A. E. Porsild

Carex leiophylla Mackenzie, sp. nov
Loosely cespitose from long-creeping, slender, stout, fibrous rootstocks, the culms 2.5-3.5 dm. high, smooth, papillose, sharply triangular, slender and more or less nodding, not at all stiff, exceeding leaves, phyllopodic, purplish-tinged and more or less fibrillose at base, the dried-up leaves of the previous year conspicuous; leaves with well-developed blades 10-15 to a fertile culm, clustered on lower fourth, the blades mostly 1-2 dm. long, 2-3.5 mm. wide, yellowish-green, papillose, flat or slightly channeled with somewhat revolute margins, thick with prominent midvein, triangular and long-attenuate towards the apex, very smooth throughout, even towards the apex, the sheaths whitish, very membranaceous, and readily breaking ventrally, the ligule as long as wide; spikes 4 or 5, sessile, very closely aggregated into an oblong-ovoid head about 2.5 cm. long and 12-16 mm. wide, the terminal gynaecandrous with a few staminate flowers at base, the lateral pistillate with 10-20 spreading-ascending perigynia closely packed in several to many rows; bracts sheathless, the lower with dilated dark-purplish base, short-prolonged but exceeded by head, the others scale-like; scales ovate or lance-ovate, acute, purplish-brown with slightly hyaline margins and apex and with slender midvein not conspicuous for its whole length, about width of but shorter than mature perigynia; perigynia ovoid, 4 mm. long, 2 mm. wide, suborbicular in cross-section and somewhat inflated, straw-colored, purplish-blotched, 2-ribbed and obscurely many-nerved, minutely granular, subcoriaceous, strongly stipitate, round-tapering at base, more or less abruptly contracted at apex, the beak 1 mm. long, bidentate, purplish, and strongly white-hyaline at the orifice; achenes triangular, oblong-obovoid, 2.25 mm. long, 1.5 mm. wide, loosely enveloped, sessile, apiculate, jointed with the slender included style; stigmas 3, slender, long.
Laxe cespitosa e rhizomatibus repentibus; culmi acute triangulares plusminus nutantes folia superantes; folia 10-15 crassa paullo revoluta glabra, costa crassa, vaginis albidis; spicae 4 vel 5 sessiles in capitulum oblongum confertae, terminalis gynaecandra basi mascula, laterales femineae, bracteis brevibus evaginatis; squamae ovatae vel ovato-lanceolatae acutae purpureo-brunneae perigyniis breviores; perigynia ovoidea 4 mm. longa straminea paullo inflata 2-costata inconspicue multinervata, in rostrum bidentatum 1 mm. longum contracta; achaenia triangularia oblongo-ovoidea apiculata.
Type collected at Carcross, Upper Yukon Valley, Alice Eastwood 725. _
Distribution: Known only from the type locality. (Specimens examined from Yukon.)