Arnica Rydbergii, Rydberg's Arnica

Arnica rydbergii is a relatively low growing species, rarely exceeding one foot, found singly or in small clusters at moderate to high elevations in mountainous areas. The flowers have between 6 and 12 broad yellow rays and several dozen yellow-orange disc florets. The bell-shaped involucre is lined by between 9 and 15 green, pointed phyllaries, all the same length; they and the stems have a fine covering of hairs. Flowerheads are usually solitary. The pappus bristles, visible between the phyllaries and the ray florets, are pure white in color, and lined by tiny barbs.

The leaves have a prominent reticulate vein pattern, and fine hairs along the lightly toothed edges. Basal leaves are persistent at flowering time.