Eriophorum triste (Th. Fries) Hadac & Á. Löve

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 : 198-199

Eriophorum triste (Th. Fries) Hadac & Á. Löve Figure 7C, D

Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82°27′37″N, 062°51′53″W; 16 m a.s.l.; 20 Jul. 2019; habitat: wetland on the margins of a lake, with peat and till as substrates, dominated by moss, Eriophorum scheuchzeri , and Eriophorum triste ; QFA 0635565.

Identification. Plants 8–19 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 7.0– 16.5 cm long; erect; glabrous. Leaves basal and cauline; alternate. Sheath margins scabrous. Ligules 0.6–1.7 mm long. Basal leaf blades 30–90 mm long, 1.3–4.0 mm wide; linear; flat or folded; straight; abaxial surface sca- brous; adaxial surface glabrous; margins scabrous. Inflo- rescence a raceme, with 2–4 spikelets; 15–30 mm long. Lower bracts shorter than the inflorescence; 13–24 mm long. Peduncles 5–18 mm long; scabrous all around the surface. Lateral spikelets and terminal spikelet bisexual, with both sexes in each floret; pedunculate; erect or pendent. Proximal scales 3.8–5.3 mm long, 2.0– 3.1 mm wide; ovate or lanceolate; greyish black sometimes purple or red-tinged, with or without narrow, hyaline margins at the apex; apices acute or acuminate. Perianth represented by bristles; white or yellowish-brown. Androecium with 3 stamens and 1.9–3.8 mm long anthers. Gynoecium with 1 style and 3 stigmas. Fruit an achene; 2.0– 2.4 mm long, 0.9–1.9 mm wide; obovoid; keeled; glabrous.

Eriophorum triste is similar to E. angustifolium subsp. angustifolium by having more than two spikelets, but can be differentiated by culms, peduncles, scale, and anther characters: E. triste has shorter culms (≤ 30 cm) than E. angustifolium (20–100 cm; Ball and Wujek 2002); E. triste has scabrous, arcuate, ≤ 2 cm peduncles, whereas E. angustifolium has glabrous (or scabrous on angles), drooping, ≤ 10 cm long peduncles (Ball and Wujek 2002; Saarela et al. 2020); E. triste has grey to black scales with or without hyaline margins, whereas E. angustifolium has brownish grey, greyish, reddish or ferruginous scales with broad hyaline margins (Ball and Wujek 2002; Saarela et al. 2020); anthers of E. triste are usually shorter (1.8–3.0 mm long) than those of E. angustifolium (2.5–5.0 mm long; Saarela et al. 2020); and fruits are obovoid, 2.0– 2.5 mm long in E. triste , whereas they are oblong-obovoid or oblong-elliptical, 2.5–3.5 mm long in E. angustifolium ( Saarela et al. 2020) . The culm height from the specimens of Alert (9–16 cm), as well as the peduncle length and scabrousity, and the fruit dimensions and shape correspond with those reported in the literature, but not the scale color and the anther length. The scales were not only grey to black, but some scales also had a reddish-purple tinge in the center. The anthers were also longer than the maximum anther length known in E triste . Only E. triste has previously been found at Alert and the surrounding areas ( GBIF 2020).

Equisetaceae – Horsetail family