Artemisia ludoviciana is a species of sagebrush known by several common names, including silver wormwood, Louisiana wormwood, white sagebrush, prairie sage and gray sagewort.

It is native to North America where it is widespread coast to coast, but many subspecies are found only in the western United States. This is a rhizomatous perennial herb growing to heights between 30 centimeters and one meter. The stems bear linear leaves up to 11 centimeters long. The stems and foliage are covered in woolly gray or white hairs. The top of the stem is occupied by a narrow inflorescence of many nodding flower heads. Each small head is a cup of hairy phyllaries surrounding a center of yellowish disc florets and is about half a centimeter wide. The fruit is a minute achene. This plant was used by many Native American groups for a variety of medicinal, veterinary, and ceremonial purposes.