Saxifraga oppositifolia Linnaeus subsp. oppositifolia

Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew & Berteaux, Dominique, 2021, Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas, Check List 17 (1), pp. 181-225 : 219

Saxifraga oppositifolia Linnaeus subsp. oppositifolia Figure 17F

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert ; 82°29′43″N, 61°57′15″W; 14 m a.s.l.; 30 Jul. 2019; habitat: xeric in a slope, with till and rocks as substrates, and sparse dominance of Salix arctica ; QFA0635002 .

Identification. Plants 1.5–3.0 cm high; herbaceous; caespitose (cushion shape) or not caespitose (trailing shape). Taproots and rhizomes present. Stems 1–6 cm long; prostrate, decumbent, or ascending; hairy, with nonglandular hairs. Leaves cauline; sometimes overlapping or imbricate; decussate; subsessile. Cauline leaf blades 2–5 mm long, 1.0– 4.5 mm wide; obovate or obtrullate; bases cuneate; unlobed; green; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs; apices rounded, obtuse, or truncate. Inflorescence a solitary flower. Sepals 5; 2.5–5.0 mm long, 1.6–2.5 mm wide; ovate; purple; surface glabrous or hairy, with nonglandular hairs; margins ciliate; apices obtuse. Petals 5; 4–8 mm long, 3–5 mm wide; obovate; unlobed; purple, pink, or white. Androecium with 9 or 10 stamens and 0.2–0.6 mm long anthers. Gynoecium with 2 styles. Fruit a capsule.

Saxifraga oppositifolia differs from all other Saxifraga species present on Ellesmere Island by having purple or pink petals ( Aiken et al. 2007; Saarela et al. 2020).