Saxifraga cespitosa Linnaeus

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 : 217-218

Saxifraga cespitosa Linnaeus

Figure 17C, D

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert ; 82°26′39″N, 61°57′18″W; 159 m a.s.l.; 26 Jul. 2019; habitat: mesic, with till and rocks as substrates, dominated by Juncus biglumis , moss, and lichen; QFA0635005 .

Identification. Plants 2.5–7.0 cm high; herbaceous; caespitose (cushion shape). Taproots and rhizomes present. Stems 1.5–6.0 cm long; erect or ascending; hairy, with glandular hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal leaves) or sessile (cauline leaves). Petioles 2–15 mm long; hairy, with glandular hairs. Basal leaf blades 3–7 mm long, 3–6 mm wide; oblanceolate or obtrullate; bases cuneate; lobed, with 3 linear or lanceolate, obtuse lobes; reddish-purple; abaxial surface sparsely hairy, with glandular hairs; adaxial surface glabrous; margins ciliate. Cauline leaf blades 3–6 mm long, 1 mm wide; linear or elliptic; abaxial

and adaxial surfaces both sparsely hairy, with glandular hairs; margins ciliate. Inflorescence a solitary flower or a cyme, with 2 or 3 flowers. Pedicels hairy. Sepals 5; 4.0– 5.5 mm long, 0.5–2.5 mm wide; ovate or lanceolate; purplish green or reddish-purple; surface hairy, with glandular hairs; margins ciliate; apices obtuse or rounded. Petals 5; 3.0– 5.8 mm long, 1.2–2.5 mm wide; oblanceolate or obovate; unlobed; pale yellow. Androecium with 9–10 stamens and 0.3–0.8 mm long anthers. Gynoecium with 2 styles.

Characteristics allowing to distinguish S. cespitosa from the other Saxifraga species present on Ellesmere Island can be found under S. cernua .