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.
Revision as of 21:03, 27 May 2020 by imported>Volume Importer

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.