Green rabbit-brush is a freely branched shrub from 20-120 cm tall. The stems are erect, with brittle twigs. The stems are glabrous with stiff spreading hairs. The leaves are 3-nerved and are linear to linear-oblong, green, and lack hairs. The leaves are curled or crisp-margined and range from 1-6 cm long and 0.5-10 mm wide. The leaves are often twisted or curled through one complete turn.
The yellow flower heads form cymose clusters at the branch tips. The flower heads are discoid and narrow, consisting of 4-8 (usually 5) flowers. The involucre is 4-8 mm high. The bracts are strongly 4-ranked withrounded to obtuse tips, glabrous and sticky. The disk corollas range from 4.5-7 mm long. Green rabbit-brush flowers from late summer into fall.
subspecies lanceolatus: Young twigs and leaves covered with tiny, short, spreading hairs. Low plants from 20-50 cm high. Leaves mostly 2-5 mm wide and 3-5 nerved. Leaves seldom twisted.
subspecies puberulus: Young twigs and leaves covered with tiny, short, spreading hairs. Low plants from 20-50 cm high. Leaves mostly 1-2 mm wide and 1-nerved.
subspecies viscidiflorus: Young twigs and leaves usually glabrous although the leaf margins may be ciliate. Plants variable in height, but may be up to 120 cm high. Leaves mostly over 1 mm wide with more than 1 vein.
Green rabbitbrush is often found with sagebrush and juniper in dry open places in the valleys, plains, and foothills. It may occasionally be found to moderate elevations in the mountains.
Green rabbitbrush is found from extreme southern British Columbia south along the east edge of the Cascades to southern California, east to Idaho and south to northern New Mexico and Arizona.