Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



David J. Keil, Family Editor and author, except as specified

Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1–many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1–many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)4–5; stamens 4–5, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):1–28. See glossary p. 25 for illustrations of general family characteristics.


Theodore M. Barkley

Perennial generally from long, naked rhizome
Leaves: basal 0 or generally withered by flower; cauline opposite
Inflorescence ± flat-topped; heads radiate or discoid, 1–many; involucre hemispheric to obconic; phyllaries generally in 2 ± equal series; receptacle ± flat, naked
Ray flowers (0)6–21; ligules (orange-)yellow
Disk flowers many; corolla generally soft-hairy, colored like ligules; anther bases entire or slightly sagittate, tips triangular; style branches flat, tips truncate, very short, hair-tufted
Fruit ± cylindric, 5–10-veined; pappus of many barbed to subplumose bristles, white to red-brown
Species in genus: ± 27 species: North America, Eurasia
Etymology: (Latin or Greek: ancient name)
Reference: [Downie & Denford 1988 Rhodora 90:245–275]
Diploid species sexual; polyploid species generally form seeds asexually.


A. longifolia D.C. Eaton

Plant 3–6 dm from caudex-like rhizome, scabrous, short-hairy upward, often ± sticky
Stems clustered, often forming large patches
Leaves: basal few, < cauline; cauline 5–7 pairs, lowest pairs often fused around stem, blade 5–12 cm, ± lanceolate, ± entire, upper ± reduced
Inflorescence: heads radiate, 3–20; involucre 7–10 mm, bell-shaped or widely obconic; phyllaries acute, glandular, ± long-hairy, (especially tip)
Ray flowers 8–13; ligules 1–2 cm
Fruit 4–6 mm, subglabrous to glandular and hairy; pappus short-barbed or subplumose, red- to yellow-brown
Chromosomes: 2n=38,±50
Ecology: Generally wet meadows or open coniferous forest
Elevation: 1800–3500 m.
Bioregional distribution: Klamath Ranges, s High North Coast Ranges, High Cascade Range, High Sierra Nevada, Great Basin Floristic Province
Distribution outside California: to w Canada, Montana, Colorado
Flowering time: Jul–Aug
Synonyms: subsp. myriadenia (Piper) Maguire
Generally asexual in CA
Horticultural information: IRR, DRN, SHD: 1, 2, 3, 4, 5, 6, 7, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

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bioregional map for ARNICA%20longifolia being generated
N.B. The distribution depicted here differs from that given in The Jepson Manual (1993)

Retrieve Jepson Interchange Index to Plant Names entry for Arnica longifolia
Retrieve dichotomous key for Arnica
Retrieve multiple-entry key (MEKA) for Arnica
Overlay Consortium of California Herbaria specimen data by county on this map
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