Polar daisy, chrysanthème polaire

Chrysanthemum arcticum Linnaeus subsp. polare Hultén, Svensk Bot. Tidskr. 43: 776. 1949; Arctanthemum hultenii (Á. Löve & D. Löve) Tzvelev; Dendranthema arcticum (Linnaeus) Tzvelev subsp. polare (Hultén) Heywood; D. hultenii (Á. Löve & D. Löve) Tzvelev

Plants (2.5–)5–20(–26) cm (more in fruit). Stems not branched. Leaves mostly basal (cauline to midstem at most); basal and proximal: petioles 4–50 mm, blades cuneate to spatulate, 6–30 × 4–16 mm, mostly 0–3-lobed; cauline: petioles 0 or 10–25 mm, blades 4–23 × 1–8 mm. Heads 1(–2), 13–20 mm diam. (flattened, excluding rays). Peduncular bracts 6–12 × 1 mm. Ray laminae (7–)9–18(–21) × (1.5–)1.8–4.3 mm, veins 4–5(–12). 2n = 18.

Flowering summer. Open, coastal, wet, brackish habitats on clay, sand, gravel, or rocks, beaches near tideline, coastal dunes, beach meadows, carex salt marshes, estuarine marshes and flood plains, coastal tundra; 0–10 m; Man., N.W.T., Nunavut, Ont., Que., Yukon; Alaska; arctic Russia.

In North America, subsp. polare ranges more or less continuously from St. Lawrence Island and the Seward Peninsula (Alaska) in the west, to the Ungava Peninsula (Quebec) in the east, along the low arctic continental coast, the coast of Hudson Bay, and the southern coast of the lower islands of the Arctic Archipelago.