Nodding Arnica

Plants 8–35 cm. Stems (1–3 together) usually simple, rarely branched (moderately to densely hairy, hairs translucent with purple septa). Leaves (2–)3–5(–6) pairs, usually crowded toward stem bases; petiolate or sessile (petioles short-winged); blades elliptic, lanceolate, or broadly oblanceolate, 3–10 × 1–2.5 cm, margins usually entire proximal to mid blade, subentire to denticulate distally, apices acute to obtuse, faces: abaxial paler and often glabrous, adaxial slightly hairy. Heads 1 (nodding). Involucres turbinate-campanulate (bases moderately villous, hairs brownish). Phyllaries 11–15, lanceolate to elliptic (apices obtuse, tips blunt, callous). Ray florets 8–13; corollas yellow (laminae 14–20 mm). Disc florets: corollas yellow; anthers dark purple. Cypselae brown, 5–6 mm, sparsely strigose (hairs simple, apically pointed) or glabrous; pappi tawny, bristles barbellate. 2n = 38, 57, 76.

Arnica angustifolia Vahl var. lessingii Torrey & A. Gray, Fl. N. Amer. 2: 449. 1843; A. lessingii subsp. norbergii Hultén & Maguire

Arnica lessingii (T. & G.) Greene, Pittonia 4: 167. 1900
Arnica alpina Less. Linnaea 6: 235, in part. 1831. Not .4. alpina Olin & Ladau, 1799. Arnica angustifolia H. & A. Bot. Beech. Voy. 126. 1832. Not A. angustifolia Vahl. 1816. Arnica angustifolia Lessingii T. & G. Fl. N. Am. 2: 449. 1843. Arnica alpina Lessingii T. & G.; A. Gray, Syn. Fl. N. Am. 1-: 383, in part. 1884*
Rootstock horizontal; stem 1.5-2 dm. high, rather densely villous with brown hairs; basal
leaves small, spatulate; stem-leaves 2 or 3 pairs near the base, the lowest oblong, elliptic, or
oblanceolate, villous and puberulent above, sparingly so or glabrate beneath, ciliate on the
margins, 4-6 cm. long, 0.5-2 mm. wide, acutish or obtusish, entire or sparingly denticulate, the
uppermost elliptic to linear, reduced; head solitary, nodding; involucre turbinate, about 15
mm. high and broad, densely villous throughout with long dark-brown hairs; bracts 12-15,
linear, obtuse; ray-flowers 8-10, the ligules about 2 cm. long, 3-4 mm. wide, deeply 2or 3-
toothed, strongly nerved; disk-corollas 7 mm. long; anthers purplish; achenes glabrous or
nearly so, strongly striate; pappus-bristles 7 mm. long, light-brown, barbellate. Perhaps not
specifically distinct from the preceding.
Type locality: Kotzehue Sound, Alaska.
Distribution: Alaska from Cape Lisburn to Alaska Peninsula and Lynn Canal, and Yukon.

Arnica lessingii is a Russian and North American species of arnica in the sunflower family. The common name is nodding arnica. It is found on both sides of the Bering Strait, being native to Alaska, Yukon, British Columbia, Northwest Territories, and the Kamchatka Peninsula of the Pacific Coast of Russia.