About Ericameria parryi (A.Gray) G.L.Nesom & G.I.Baird
Ericameria parryi, synonym Chrysothamnus parryi, is a flowering plant species in the Asteraceae family, commonly called Parry's rabbitbrush. It is native to most of the western United States. This species is highly variable, with specific traits distinguishing its many varieties. In general, it is a shrub that produces several upright stems growing between 10 centimeters and one meter tall, though it rarely reaches the maximum one meter height. Its branches are covered in a fuzzy layer of white or greenish fibers. Leaves range from linear to spatula-shaped, and measure between 1 and 8 centimeters long. Leaf texture can be hairless, quite hairy, or woolly, and leaves may be glandular and sticky. The inflorescence is often a cluster of many flower heads, though sometimes flower heads grow singly. Each flower head holds up to 20 yellow disc florets, and has no ray florets. The fruit is an achene up to 8 millimeters long, tipped with a whitish or brown pappus that reaches up to 7.5 millimeters in length. Flowering occurs primarily from July through September, and achenes develop and disperse through fall and into winter. Seeds are dispersed by wind. The plant has a lifespan of 15 to 20 years. This hardy species grows in a variety of habitat types, including mountains and foothills, and its populations often increase after environmental disturbances such as grazing. There are at least 12 recognized varieties: Ericameria parryi var. affinis, which is limited to Colorado, New Mexico, and Arizona; Ericameria parryi var. aspera, or rough rabbitbrush, limited to California and Nevada; Ericameria parryi var. attenuata, or narrow-bract rabbitbrush; Ericameria parryi var. howardii, or Howard's rabbitbrush, found in and east of the Rocky Mountains; Ericameria parryi var. imula, or low rabbitbrush, a small-statured variety endemic to Bear Valley in San Bernardino County, California; Ericameria parryi var. latior, or broadleaf rabbitbrush, limited to northern California; Ericameria parryi var. monocephala, or one-headed rabbitbrush, common in the Sierra Nevada of eastern California and western Nevada; Ericameria parryi var. montana, or mountain rabbitbrush, a small plant known only from the Red Conglomerate Peaks of Idaho and Montana; Ericameria parryi var. nevadensis, or Nevada rabbitbrush; Ericameria parryi var. parryi, widespread across the interior western United States; Ericameria parryi var. salmonensis, or Salmon River rabbitbrush, endemic to Idaho where it grows along the Salmon River; and Ericameria parryi var. vulcanica, or Vulcan rabbitbrush, an uncommon small variety endemic to California's Sierra Nevada.
