Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas Author Desjardins, Émilie Author Lai, Sandra Author Payette, Serge Author Dubé, Martin Author Sokoloff, Paul C. Author St-Louis, Annie Author Poulin, Marie-Pier Author Legros, Jade Author Sirois, Luc Author Vézina, François Author Tam, Andrew Author Berteaux, Dominique text Check List 2021 2021-02-09 17 1 181 225 http://dx.doi.org/10.15560/17.1.181 journal article 10.15560/17.1.181 1809-127X × Pucciphippsia vacillans (T. Fries) Tzvelev Figure 11M Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°26′40″N , 062°43′09″W ; 210 m a.s.l.; 14 Jul. 2019 ; habitat: mesic, with peat and till as substrates, dominated by Juncus biglumis , moss, and blue-green algae (macroscopic sheet colonies dominated by Nostoc sp. ); QFA 0635516, CAN • same locality; 82°27′49″N , 062°34′42″W ; 126 m a.s.l.; 25 Jul. 2019 ; hab- itat: wetland, with tussocks made of peat and till, dominated by Eriophorum triste , Arctagrostis latifolia , and Alopecurus magellanicus ; QFA 0635588. Identification. Plants 3.5–13.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 1–10 cm long; erect, ascending, or semi-prostrate; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.9– 1.3 mm long. Basal leaf blades 25–60 mm long, 0.7–1.1 mm wide; linear; folded or rolled in bud; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 12–15 mm long, 0.9–1.1 mm wide. Inflorescence a dense or diffuse panicle; 18–35 mm long. Branches at lowest inflorescence node 4–6; 2–10 mm long. Pedicels glabrous. Spikelets 2.2–2.5 mm long, 0.8–1.2 mm wide. Florets per spikelet 1–3. First glumes 0.5–0.7 mm long; ovate; surface glabrous; margins glabrous; apices obtuse. Second glumes 0.8–1.1 mm long (shorter than the lowest floret); ovate; veins 1–3; surface glabrous; margins gla- brous; apices obtuse. Lemmas 2.0– 2.3 mm long, 0.6–0.8 mm wide; lanceolate; rounded on the back; veins 3; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous; awnless. Palea 2.0– 2.2 mm long; veins hairy. Rachilla between first and second lemmas 0.4–0.7 mm long. An- droecium with 3 stamens and 0.7–1.2 mm long anthers. Gynoecium with 2 styles. Fruit not seen at Alert. Characteristics allowing to distinguish × P. vacillans from Phippsia can be found under P. algida . Polygonaceae – Buckwheat family