Arnica cordifolia

           Heart-Leaved Arnica

Flower Head Top in Ground

Centre Block, Cypress Hills Interprovincial Park
16-June-2008

Note that the key to the species in Budd's Flora requires stem leaves long-petioled; NOT [stem leaves with the petiole shorter than the blade].  In fact, the lower stem leaves are petioled but the petiole may be longer or shorter than the blade.  The key to the species in Flora of Alberta requires both pappus often white or subplumose; NOT [pappus straw-coloured or brownish, barbellate] and pappus scabrous or barbellate; NOT [pappus subplumose].  In fact, the pappus is white and barbellate.

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Cordifolia: Answers to key questions in Budd's Flora (BF)  and Flora of Alberta (FOA) leading to this species. 
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plants 2-6 dm tall; NOT [plants 1-3 dm tall] (FOA)

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stems solitary or few; NOT [plants tufted] (FOA)

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basal leaves often conspicuous; NOT [tufts of basal leaves not evident on the flowering stems] (FOA)

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basal leaves usually long-stalked; NOT [basal leaves usually short-stalked or stalkless] (FOA)

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basal leaves cordate or broadly ovate; NOT [basal leaves linear to lanceolate or oblanceolate] (FOA)

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lower leaves usually cordate; NOT [lower leaves seldom cordate] (FOA)

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cauline leaves mostly 2-4 pairs, not including those (if any) of the basal cluster; NOT [cauline leaves mostly 5-10 pairs] (FOA)

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stem leaves long-petioled; NOT [stem leaves with the petiole shorter than the blade]  (BF)

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larger stem leaves cordate or ovate; NOT [stem leaves oblong]  (BF)

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leaves cordate to oblong; NOT [leaves oblong-lanceolate to linear]  (BF)

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leaves usually more than 2.5 cm wide; NOT [leaves usually 2.5 cm wide or less] (FOA)

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heads 1-3; NOT [heads 3-9] (FOA)

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heads erect or nearly so in the bud; NOT [heads nodding in the bud] (FOA)

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bracts 10-18 mm long; NOT [bracts 7-9 mm long] (FOA)

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base of involucre white-pilose; NOT [base of involucre sparingly hairy] (FOA)

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involucre more than 1 cm wide; NOT [involucre about 1 cm wide] (FOA)

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rays present; NOT [rays lacking] (FOA)

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achenes hairy and/or glandular; NOT [achenes glabrous, at least at base] (FOA)

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pappus white; NOT [pappus straw-coloured or brownish] (FOA)

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pappus scabrous or barbellate; NOT [pappus subplumose] (FOA)

 

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Arnica: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.
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juice watery; NOT [juice milky] (FOA)

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leaves opposite; NOT [leaves alternate or basal] (FOA)

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involucral bracts usually one series, not or scarcely imbricated; NOT [involucral bracts in 2 or more series, well imbricated] (BF)

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receptacle naked (FOA)

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flower heads with florets both tubular and ray

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ligulate flowers when present pistillate or neuter; NOT [flowers all perfect] (FOA)

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ray florets yellow; NOT [rays white, to pink, purple or blue]

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stamens united to form a tube around the pistil (BF)

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pappus composed of hairs; NOT [pappus chaffy, or of firm awns, or of bristles, or of scales, or a crown or none]