Yellow flowers of shrubby rabbitbrush cover the roadsides in fall in the mountain west. Rabbitbrush are woody shrubs on the banks of desert arroyos and along roadside ditches throughout much of the southwest. A number of species occur, the most common being nauseosus. Only disc flowers are present. Chrysothamnus means "golden shrub". Ericamera is greek for heath like leaves.

Ericamera larcinifolia
Specimen growing in garden at Sonoran Desert Musem, Tucson, Arizona.
Ericamera

nauseosus

Rubber Rabbitbrush

Rubber Rabbitbrush, of which there are too many varieties to name here, is seen all over the mountain west. Keying out Ericamera I have observed a stunning variety ofnauseous varieties in Colorado, New Mexico, Utah, and Arizona. A larger nauseosus like the overall above can be over 2 meters (6.5 feet) tall.
Ericamera

pulchellus

Southwestern Rabbitbrush

 
This specimen of pulchellus was growing in the desert terrain about 10 miles east of Socorro, New Mexico in sandstone and shale barrens. The phyllaries on the side of the flowers and the tiny teeth on leaf margins clearly distinguish this species from nauseosus.
Ericamera

viscidiflorus

Green Rabbitbrush

Green Rabbitbrush is distinguished by the sticky foliage and corkscrew leaves. This specimen was photographed in meadows along Taylor Creek above Almont, Colorado at an elevation of 8,400 feet on July 1, 2007. Height 21 in. to a meter. Lower stems are woody, upper stems greenish. Leaves twisted, length 40 mm, width 3 mm, clearly five nerved with center nerve
prominent.