Braya thorild-wulffii Ostenfeld

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 : 190

Braya thorild-wulffii Ostenfeld subsp. thorild-wulffii Figure 5B

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°27′20″N, 062°03′05″W; 142 m a.s.l.; 26 Jul. 2019; habitat: xeric with polygonal patterned ground made of till and rocks, and sparse dominance of Puccinellia bruggemannii T.J. Sørensen and Stellaria longipes Goldie ; QFA 0635557, CAN • same locality; 82°29′09″N, 062°00′03″W; 36 m a.s.l.; 30 Jul. 2019; habitat: mesic in a slope, with hummocks made of till and rocks, dominated by Stellaria longipes and moss; QFA 0635589.

Identification. Plants 1.5–6.0 cm high; herbaceous; caespitose. Taproots present. Stems 1.0– 5.5 cm long; decumbent or prostrate; hairy, with simple hairs. Leaves basal; alternate; petiolate. Petioles 2–4 mm long; winged; margins glabrous or ciliate, with simple hairs. Leaf blades 3–10 mm long, 1.1–2.5 mm wide; oblanceolate or obtrullate; bases attenuate; abaxial surface sparsely hairy, with simple hairs; adaxial surface glabrous; margins ciliate, with simple hairs; apices obtuse. Inflorescence a raceme, with 2–4 flowers; elongating as the fruit matures. Pedicels hairy. Sepals 4; 2.0– 2.6 mm long, 1.1–1.5 mm wide; ovate or oblong; green or purple; surface hairy, with simple hairs; margins ciliate; apices obtuse. Petals 4; 1.3–3.4 mm long, 0.8–1.6 mm wide; obovate; unlobed; white. Androecium with 6 stamens and 0.2–0.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 4–10 mm long, 2.1– 3.7 mm wide; ovoid or spherical; purple or green; hairy, with simple hairs. Styles persisting in fruit 0.05–0.10 mm long, 0.3–0.7 mm wide. Stigmas 0.4–0.8 mm wide; slightly larger than the styles.

Characteristics allowing to distinguish B. tho- rild-wulffii subsp. thorild-wulffii from the other Braya species on Ellesmere Island can be found under B. purpurascens .