Arnica lessingii

(Torrey & A. Gray) Greene

Pittonia 4: 167. 1900.

Common names: Nodding arnica
Basionym: Arnica angustifolia var. lessingii Torrey & A. Gray Fl. N. Amer. 2: 449. 1843
Synonyms: Arnica lessingii subsp. norbergii Hultén & Maguire
Treatment appears in FNA Volume 21. Treatment on page 369. Mentioned on page 366, 367.

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.


Phenology: Flowering Jun–Sep.
Habitat: Coastal tundra to alpine slopes
Elevation: 0–1500 m

Distribution

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B.C., N.W.T., Yukon, Alaska, Asia (Russian Far East).

Discussion

Selected References

None.

Lower Taxa

None.