Arnica (_Arnica montana_) is a herbaceous perennial plant of the aster
family, native in northern and central Europe, where it thrives in the
cool climate of the mountain meadows and upland moors. The flowers,
leaves, and roots are employed in medicine.
Arnica requires a marshy soil, abundant rainfall, and a cool climate
for its best development. It is propagated by divisions of the roots
or from seeds sown either in the fall or the spring. Seed may also be
sown in August in a seed bed and the plants transplanted the following
spring to stand about 18 inches apart in the row. The flowers may be
harvested the second year and the roots after three or four years.
Arnica is not produced commercially in the United States, and the small
quantity imported annually is apparently sufficient to meet the market
demands. Its cultivation presents many difficulties, and efforts to
grow it in the milder portions of this country have generally proved
unsuccessful.