Western mugwort (Artemisia ludoviciana) has a multitude of common names including, but not limited to, silver wormwood, prairie sage, white sagebrush, grey sagewort. Calling any Artemisia a “sage” is incorrect because this genus, a member of the Aster Family, is not related to any of the sages, which are mints. Artemisia contains many pungent, aromatic species which smell similar to sage hence the name. The appellation wormwood probably derives from the fact that western mugwort, and other Artemisia species, were used as vermifuges (medicine that expels intestinal worms). Similarly mugwort, from the Old English meaning “fly plant”, may refer to the insect repelling properties of some Artemisia plants.
A perennial that is currently found (native or introduced) throughout most of North America, western mugwort grows on dry slopes and in canyons and meadows, often associated with oaks and conifers.
Western mugwort stems arise from creeping rhizomes and usually grow from about 1 1/2 to 3 feet in height. The multiple stems are rarely branched.
The alternate, semi-evergreen leaves of western mugwort are lance shaped and mostly entire. The lower leaves are sometimes lobed or pinnately divided. The leaves are tomentose (covered with densely matted woolly hairs) giving the plant a white or silver appearance – the white, silver or grey of colloquial names.
The narrow inflorescences at the top of the stems are composed of many flower heads. The flower heads of western mugwort are composed of up to 45 yellow or brownish disk flowers surrounded by green, hairy phyllaries (bracts around the flower heads).
Western mugwort fruits are tiny achenes without bristles.
Although western mugwort (along with all the Artemisia species) are generally considered toxic, over the course of history it has been used as a medicine. Artemisia teas were taken to purge intestinal parasites and to stop internal bleeding. Members of this genus also have strong bacteriostatic properties so were used as a skin wash and for infections. The allergenic properties of plants in the Artemisia genus can cause problems if used in this manner, These plants should not be used as medicine.
Western mugwort is extensively cultivated as an ornamental.
The species, ludiviciana, is the Latinized name of Louisiana. It may refer to the State of Louisiana, where western mugwort grows, to the Louisiana Purchase or perhaps even to the city of St. Louis. All three derivations are noted in the literature.
These western mugwort specimens were photographed in the meadow upstream of the Lower Ash Creek Campground (Modoc County CA) in July.