Ranunculus sabinei R. Brown

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 : 213

Ranunculus sabinei R. Brown

Figure 14A

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert ; 82°27′54″N, 062°46′43″W; 14 m a.s.l.; 8 Jul. 2019; habitat: wetland surrounded by hills, with silty sand as substrate, dominated by Alopecurus magel- lanicus; QFA0634990 .

Identification. Plants 3–7 cm high; herbaceous; not caespitose. Fibrous roots present. Stems 2.5–6.0 cm long; erect or ascending; hairy, with hyaline hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal leaves) or sessile (cauline leaves). Petioles 5–14 mm long; glabrous. Basal leaf blades 6–10 mm long, 4–11 mm wide; widely depressed ovate or suborbicular; bases cuneate, obtuse, or truncate; lobed, with 3–5 main palmate, obtuse lobes; abaxial surface glarous or sparsely hairy, with hyaline hairs; adaxial surface glabrous; margins ciliate. Cauline leaf blades 6–9 mm long, 5–8 mm wide; lobed, with 3 deeply cleft, linear, obtuse lobes; abaxial surface glabrous; adaxial surface glabrous or sparsely hairy, with hyaline hairs; margins ciliate. Inflorescence a solitary flower. Sepals 5; 4–7 mm long, 2.0– 3.5 mm; lan- ceolate, ovate, or obovate; pale brown or pinkish-brown, with hyaline margins; surface hairy, with hyaline hairs; margins glabrous or hairy; apices rounded or obtuse. Petals 5; 4–7 mm long, 2–4 mm wide; obovate; unlobed; yellowish-purple. Androecium with 20–30, 2.0– 3.3 mm long stamens. Receptacle 3–6 mm high; surface glabrous or sparsely hairy, with hyaline hairs. Fruit an achene; 0.9–1.4 mm long, 0.7–1.0 mm wide; ovoid; yellowishgreen; with curved beak; glabrous.

Ranunculus sabinei is similar to R. arcticus and R. pygmaeus , both of which are found on Ellesmere Island, by having white or translucent hairs on sepals, but differ in the following characters: leaf blades of R. sabinei and R. pygmaneus are usually 3-lobed, whereas they are 5- to 9-lobed in R. arcticus ; sepals of R. sabinei are bigger (4–7 mm long, 2–3 mm wide) than those of R. pygmaeus (2–4 mm long, 1.2–1.6 mm wide); and petals of R. sabinei are longer (5–8 mm long) than those of R. pygmaeus (1.2–3.5 mm long) but shorter than those of R. arcticus (7–15 mm long; Saarela et al. 2020).