Arnica (Arnica montana)

Its native habitat includes grasslands, shrub lands, and alpine mountain environments.  It can also be found in meadows, dry pine forests, open forests, and pastures.  
It grows .5 to 2 feet tall with basal downy leaves and flowers that occur May to August. The yellow-orange ray flowers surround the yellow disc florets are followed by achenes. The flowers form as a solitary bloom at the top of each stem.  In windy locations, they may need to be staked for additional support.  Cutting the stem back before the plant flowers will keep the stems short, as well as produce a secondary bloom.  Divide during the spring or fall every few years to keep this plant at its best.  Their roots can spread, taking over more space than intended.  Maintain this plant to avoid invading other portions of your garden.
It tolerates most soils if they are lime free, and a well-drained location in full sun to partial shade, but prefers slightly alkaline moist sandy loam. 
This plant is toxic, however, has been listed as endangered in many locations due to its collection for medicinal uses.  
Zone: 5 to 8
Height: .50 to 1.00 feet
Spread: .50 to 1.00 feet
Bloom Time: May to July
Sun: Full sun
Water: Medium
Tolerate: Deer