Draba pauciflora 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 : 193-194

Draba pauciflora R. Brown

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert ; 82°29′58″N, 062°33′36″W; 66 m a.s.l.; 11 Aug. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Stellaria longipes ; QFA0635550 , CAN .

Identification. Plants 1.7–3.5 cm high; herbaceous; caespitose. Taproots present. Stems 0.4–3.0 cm long; erect or ascending; hairy, with simple and branched hairs (2–3 rays: T, V, Y, and ternate). Leaves basal; alternate or whorled; petiolate or subsessile. Petioles 2–5 mm long; winged; margins glabrous or ciliate, with simple hairs. Basal leaf blades 5.2–9.0 mm long, 1.8–3.4 mm wide; oblanceolate or obtrullate; bases attenuate; abaxial surface moderately hairy, with simple and branched hairs (2–5 rays: Y, T, ternate, and dendritic); adaxial surface sparsely to moderately hairy, with simple and branched hairs (2 rays: Y); margins ciliate, with simple long hairs; apices acute. Inflorescence a raceme, with 2–5 flowers; elongating or not elongating as the fruit matures. Pedicels 1.5–4.0 mm long; hairy. Sepals 4; 2.3–2.5 mm long, 0.8–0.9 mm wide; ovate or oblong; yellow, with hyaline margins; surface hairy, with simple and branched hairs (2 rays: Y); margins glabrous; apices obtuse. Petals 4; 2.9– 4.0 mm long, 1.2–1.8 mm wide; obovate or oblanceolate; unlobed, slightly lobed, or undulating; white or pale yellow. Androecium with 6 stamens and 0.2–0.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 5.5–10.0 mm long, 1.8–4.0 mm wide; lanceolate or

elliptic; flattened; green; hairy, with simple and branched hairs (2 rays: Y, T, and V). Styles persisting in fruit 0.2– 0.4 mm long, 0.3–0.5 mm wide. Stigmas 0.4–0.7 mm wide; larger than the styles.

Characteristics allowing to distinguish D. pauciflora from the other yellow-flowered Draba species present on Ellesmere Island can be found under D. corymbosa and D. micropetala .