Puccinellia angustata (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 : 209-210

Puccinellia angustata (R. Brown) E.L. Rand & Redfield

Figures 10F, 11J

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°31′04″N, 062°28′48″W; 66 m a.s.l.; 27 Jul. 2019; habitat: mesic, with hummocks made of till, dominated by Stellaria longipes , Saxifraga oppositifo- lia, and moss; QFA 0635529 • same locality; 82°29′56″N, 062°19′19″W; 48 m a.s.l.; 8 Aug. 2019; habitat: xeric near the sewage outlet, with till and rocks as substrates, and sparse dominance of Puccinellia angustata and Cochle- aria groenlandica ; QFA 0635530.

Identification. Plants 10.5–24.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 8–21 cm long; erect, ascending, or prostrate; glabrous and sometimes scabrous below the inflorescence. Leaves basal and cau- line. Sheath margins glabrous or scabrous. Ligules 1.3– 1.7 mm long. Basal leaf blades 25–84 mm long, 0.7–0.9 (1.4–1.5 flat) mm wide; linear; rolled in bud or flat; abax- ial and adaxial surfaces both glabrous; margins glabrous or scabrous. Flag leaf blades 26–48 mm long, 0.3– 0.1 mm wide. Inflorescence a diffuse or dense panicle; 30– 57 mm long. Branches at lowest inflorescence node 3; 2.9–11.5 mm long. Pedicels scabrous. Spikelets 4.1–6.7 mm long, 1.5–2.0 mm wide. Florets per spikelet 3–5. First glumes 1.0– 1.6 mm long; lanceolate; surface glabrous; margins scabrous; apices acuminate. Second glumes 2.4– 2.8 mm long (shorter than the lowest floret); lanceolate; veins 3; surface glabrous; margins scabrous; apices acuminate. Lemmas 3.0– 3.9 mm long, 0.6–0.8 mm wide; lanceolate; rounded on the back and with straight lemma tips; veins 4 or 5; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous or scabrous; awnless. Palea 2.4–2.8 mm long; veins hairy proximally, with curly simple hairs, and scabrous apically. Rachilla between first and second lemmas 1.0– 1.5 mm long. Androecium with 3 stamens and 0.8–1.2 mm long anthers. Gynoecium with 2 styles.

There are seven Puccinellia Parlatore species present on Ellesmere Island ( GBIF 2020). One of them, P. phryganodes subsp. neoarctica , is spreading by leafy stolons, whereas the others are caespitose and do not have stolons (Consaul and Gillespie 2001; Aiken et al. 2007). The remaining species can be separated using the following combination of characters: in P. angustata , P. bruggemannii , and P. vahliana the palea veins have curly, intertwined hairs proximally and are scabrous apically, in contrast to being glabrous proximally and scabrous or smooth distally in P. andersonii Swallen , P. arctica (Hooker) Fernald & Weatherby , and P. vaginata (Lange) Fernald & Weatherby ( Aiken et al. 2007; Saarela et al. 2020). Among the three former species, P. vahliana has smooth pedicels, whereas they are scabrous in P. angustata and P. bruggemannii ( Saarela et al. 2020) . Inflores- cences, second glumes, and lemmas are reported to be longer in P. angustata (inflorescences 4–13 cm long; sec- ond glumes 1.9–3.0 mm long, with a length-width ratio

of 0.3–0.6; lemmas 3.5–5.2 mm long) than in P. bruggemannii (inflorescences 1–4 cm long; second glumes 1.7–2.3 mm long, with a length-width ratio of 0.5–0.8; lemmas 2.8–3.8 mm long; Saarela et al. 2020). However, we found that using only the length of the inflorescences, glumes, and lemmas did not unambiguously differentiate the two species. Indeed, we had specimens of P. angustata with shorter inflorescences (e.g., 3 cm long) and lem- mas (e.g., 3 mm long), and specimens of P. bruggemannii with longer inflorescences (e.g., 4.5 cm long), glumes (e.g., 2.9 mm long), and lemmas (e.g., 4 mm long). We found however that the presence of incurved lemma tips in P. bruggemannii and straight lemma tips in P. angustata was a good identification criterion, as well as an anther length> 0.8 mm and a plant height> 10 cm ( Consaul et al. 2008a; Saarela et al. 2020).