Arnica cordifolia (Heartleaf Arnica)
Asteraceae (Sunflower Family)

Montane, subalpine. Woodlands. Summer.
Lizard Head Trail, June 19, 2004.

This is a most common and bright mountain flower and the most common of all Arnicas in the Four Corners area.  It thrives in the dry, acid soils under Spruce and as one enters the dark forest shade from sunny meadows, the bright lemon-yellow Arnica flowers are like beams of lights.  It is common to see dozens of flowering Arnica plants in one patch with hundreds of leafy, flowerless plants carpeting the ground around them.

Since seeds of Arnica cordifolia are produced without fertilization, off-spring are genetically identical to their parents.  The patches of Arnica cordifolia are, therefore, clones and this accounts for the wide variability of Arnica cordifolia characteristics from one location to another: since there is no pollination there is no blending of characteristics to a common denominator.

"Cordifolia" means "heart-leaf", but, although the heart-shape is often evident, Arnica cordifolia leaf shape is highly variable (the top leaves in the photo are elongated triangles, the bottom are heart-shaped).  The word "Arnica" means "lamb's skin," and probably refers to the downy soft leaves.

Thomas Drummond collected the first specimen of Arnica cordifolia (as well as Arnica mollis shown on another page) in the Canadian Rockies in the 1820s and it was named by William Hooker in his Flora Boreali-American in 1834.

Arnica cordifolia (Heartleaf Arnica)
Asteraceae (Sunflower Family)

Montane, subalpine. Woodlands. Summer.
Lizard Head Trail, June 19, 2004 and Sneffels Highline Trail, August 4, 2004.