Alex Hyde / Nine-spotted moth (Amata phegea) feeding from a Mountain arnica flower (Arnica montana) Triglav National Park, Julian Alps, Slovenia. July.

Jack Dykinga / Heartleaf arnica {Arnica cordifolia} flowering in coniferous forest, tree trunks show charring from the great 1988 forest fire, Mount Washburn, Yellowstone NP, Wyoming, USA

Wild Wonders of Europe / Benvie / Mountain arnica (Arnica montana) with Fritillary butterfly (Boloria sp) on flower, Naturpark Kaunergrat, Tirol, Austria, July 2008

Fabrice Cahez / Arnica flower (Arnica montana) Cantal, France, July.

Nick Garbutt / Fritillary butterfly (Melitea varia) feeding on Mountain Arnica (Arnica montana). Nordtirol, Austrian Alps, Austria, July.

Alex Hyde / Heath Fritillary (Melitaea athalia) on Mountain Arnica (Arnica montana). Nordtirol, Austrian Alps. June.

Alex Hyde / Mountain Arnica (Arnica montana) Nordtirol, Austrian Alps. June.

MYN / Niall Benvie / Leopardsbane (Doronicum pardlianches) in flower, Scotland, UK, May.

Jussi Murtosaari / Arnica flower (Arnica angustifolia) Enontekia, Lappi / Lapland, Finland. July

Radomir Jakubowski / Wolf's bane (Arnica montana) in dewy grassland, Vosges Mountains, France, June.

Radomir Jakubowski / Wolf's bane (Arnica montana) Vosges Mountains, France, June.

Fabrice Cahez / Mountain arnica (Arnica montana) close up of flower, Aubrac, Auvergne, France, July.