Nevada designated sagebrush (Artemisia tridentata) as the official state flower in 1917. Sagebrush bushes grow up to 12 feet (along rivers or other relatively wet areas - more typically it grows 3-6 feet in height) and produces small yellow and white flowers in the late summer or early fall.

Sagebrush (also called big sagebrush, common sagebrush, blue sagebrush, or black sagebrush) is a coarse, hardy ,silvery gray-green bush that grows in the desert southwest of the United States. It has a strong pungent fragrance, especially when wet. Native American Indians used the leaves of sagebrush for medicine and sagebrush bark for weaving mats.

Source:

State Symbols: Nevada First Lady Dawn Gibbons
Artemisia tridentata: Wikipedia.org

Links:

State Flowers - 50 States List
National Flower