B and T World Seeds' reference number: 445882
USDA average, annual, minimum temperature Zone:4
Type of plant - perennial
Flower: pale to deep YELLOW, infl. 7-20, in capit.
Height in meters: 0.6
Parts of Arnica longifolia are considered toxic.

Arnica longifolia is included in the following B and T World Seeds flowering plant categories:
6:   Bulbous and Rhizomatous Plant Seed List
43:   Herbaceous Border Plant Seed List
76:   Californian Native Plant Seed List
88:   Natives of U.S.North West
94:   Natives of Rocky Mountain Area U.S.A.
185:   Plant Species whose germination is improved by Smoke
246:  Asteraceae
708:  Compositae

Germination guide
Arnica longifolia seeds will usually germinate in 25-30 days. Sow seeds about 1mm deep in a Well drained seed sowing mix at about 12°C.

Likes an acid sandy soil.