Salix arctica Pallas, 1788

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 : 214-216

Salix arctica Pallas

Figure 16A–C

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 ; QFA0635521 .

Identification. Plants 2–5 cm high; dwarf shrubs. Fibrous roots present. Branches erect, decumbent, or

trailing; glabrous. Branchlets glabrous or hairy, with long hyaline hairs. Leaves deciduous; cauline; alternate; petiolate. Stipules 1.3–1.5 mm long; green; deciduous. Petioles 1.1–4.9 mm long; glabrous or hairy. Cauline leaf blades 5.6–19.5 mm long, 2.5–7.5 mm wide; elliptic, oblanceolate, or obovate; bases obtuse, cuneate, or rounded; green; abaxial surface glaucous and hairy, with long hyaline hairs; adaxial surface dull or shiny, and glabrous or sparsely hairy, with long hyaline hairs; margins entire, flat, and ciliate; apices obtuse or acute. In- florescences catkins. Plants dioecious. Peduncles hairy. Staminate catkins 14–25 mm long, 6–10 mm wide. Pistillate catkins 10–30 mm long, 8–14 mm wide; Bracteoles 0.8–1.6 mm long, 1.0– 1.2 mm wide; reddish-brown or black; surface hairy, with white hairs; apices rounded or obtuse. Androecium with 2 stamens and 0.3–0.5 mm long anthers. Gynoecium with hairy (white hairs) pyriform ovaries (2.2 mm long, 1 mm wide), 1.1–1.3 mm long styles, and 0.3–0.6 mm long stigma lobes.

Salix arctica and S. arctophila Cockerell ex A. Heller are the only Salix Linnaeus species present on Ellesmere Island ( GBIF 2020) and can be distinguished based on the following: the largest medial leaf blade abaxial surface is glabrous in S. arctophila , whereas it is usually pilose in S. arctica (sometimes the midrib is sparsely short-silky and the apex is long-silky bearded; Saarela et al. 2020); leaf blade margins are serrulate or crenulate (sometimes entire) in S. arctophila , whereas the margins are entire in S. arctica ( Saarela et al. 2020) ; and the ovary hairs are white and rust-couloured, appressed, crinkled, and ribbon-like in S. arctophila , whereas the hairs are only white, flattened, and wavy (not crinkled) in S. arctica ( Aiken et al. 2007) .

Saxifragaceae – Saxifrage family