Sabulina rossii (R. Brown ex Richardson) Dillenberger & Kadereit

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°27′34″N, 062°44′57″W; 118 m a.s.l.; 16 Aug. 2019; habitat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Juncus biglumis Linnaeus and moss; QFA0635571.

Identification. Plants 1–3 cm high; herbaceous; caespitose. Taproots present. Stems 0.5–1.5 cm long; prostrate, decumbent, or ascending; glabrous. Leaves cauline; opposite; sessile. Leaf blades 2–3 mm long, 0.3–1.0 mm wide; elliptic or linear; upwardly curved; appearing single-veined or veins inconspicuous; green, dark purple, or dark red; abaxial and adaxial surfaces both glabrous; margins glabrous; apices obtuse. Inflorescence a solitary flower. Pedicels glabrous. Sepals 5; 1.0– 2.8 mm long, 0.5–1.3 mm wide; ovate; purple; surface glabrous; margins glabrous; apices obtuse or acute. Petals 5; 2–3 mm long, 0.7–1.2 mm wide; oblong or obovate; unlobed; white. Androecium with 10 stamens and 0.4–0.5 mm long, yellow anthers. Gynoecium with 3 styles and 1 stigma per style.

The only two Sabulina Reichenbach species present on Ellesmere have been found in our survey (Aiken et al. 2007; GBIF 2020). They differ in a few characters: S. rossii has glabrous stems, whereas S. rubella has pubescent stems with glandular hairs (Blondeau et al. 2015b; Saarela et al. 2020), and S. rossii has single-veined (if vein apparent) leaf blades,whereas S. rubella has threeveined leaf blades (Aiken et al. 2007).