Arnica chamissonis
 
Leafy Arnica

Upper Plant in Ground

Duck Mountain Provincial Park
26-July-2009

Note that each pair of opposite leaves is at right angles to the pair immediately above it and the pair immediately below it.  Leaves arranged in this manner are called decussate.

bullet

Chamissonis: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 
bullet

stem leaves numerous, in 4-8 pairs; NOT [stem leaves less numerous, in 1-3 pairs] (BF)

bullet

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

bullet

leaves oblong-lanceolate to linear; NOT [leaves cordate to oblong]

bullet

lower stem leaves lanceolate; NOT [lower stem leaves ovate or deltoid]

bullet

lower stem leaves entire to remotely dentate; NOT [lower stem leaves sharply dentate]

bullet

heads several to many; NOT [heads solitary or few]

bullet

involucral bracts obtuse or merely acutish; NOT [involucral bracts definitely acute]

bullet

involucral bracts bearing a tuft of long hairs at or just within the tip; NOT [tips of involucral bracts not markedly more hairy than the body]

bullet

pappus straw-coloured or brownish; NOT [pappus often white]

bullet

pappus barbellate; NOT [pappus often subplumose]

 

bullet

Arnica: Answers to key questions in Budd's Flora  and Flora of Alberta leading to this genus. 
bullet

juice watery; NOT [juice milky]

bullet

leaves opposite; NOT [leaves alternate or basal]

bullet

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

bullet

receptacle naked (FOA)

bullet

flower heads with florets both tubular and ray

bullet

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

bullet

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

bullet

stamens united to form a tube around the pistil

bullet

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