California Mugwort

Artemisia douglasiana

yellow cluster of small flowers tangled together
La Orilla revegetation area | August 2018

California mugwort (Artemisia douglasiana) is a relative of the California sagebrush, to which it bears little resemblance. The small, inconspicuous flowers are similar and both have aromatic leaves. The leaves of mugwort, however, are not small and finely divided like those of sagebrush, but are rather large and broad, green on top and white below. Also, California mugwort needs a fairly consistent source of fresh water. Look for it near willows and mulefat.

California mugwort has a long history of use, as a treatment for arthritis and bronchitis, as an insect repellent and ghost repellent. The Chumash, Native Americans of the Santa Barbara area, used the wool from the leaves to cauterize wounds and they used the leaves as a treatment for poison oak. The Luiseño, from Oceanside and north, made arrows from the stems, while the Kumeyaay people prepared a tea from the leaves for use as a decongestant.

Other Common Names:

Douglas' sagewort

Description 4,11,24,59,

California mugwort is a perennial herb that dies back in the winter.290 Tall, largely unbranched stems arise from subsurface rhizomes. Leaves are cauline, with short petioles, larger below, gradually decreasing in size; lengths vary from one to seven inches (2.5-17.5 cm). The upper leaf surface is smooth and dark green; the lower surface is white with dense woolly hairs.  Most leaves are narrowly to broadly ovate or obovate with smooth margins. Larger leaves may be incised toward the apex, creating a few small teeth or larger, sharp lobes. The crushed leaves are highly aromatic, an odor likened to sage,4 to a cross between sage and camphor,35and to turpentine, kerosene or tar – sometimes with a hint of citrus.59

Flowers occur at stem ends in long, complex clusters with several orders of branching. The primary unit is the flower head, a structure composed of several individual flowers (florets) on a common base that is surrounded by specialized leaf-like structures (phyllaries). A flower head is about 3/32 inch (0.2-0.33 cm) across and 3/16 inch (0.5 cm) long. Three to ten flower heads are clustered into larger spike-like clusters that in turn are arranged along short lateral branches that spread from the main stem. A small leaf-like bract arises from each branching node, giving the cluster a leafy appearance. Each flower head consists of five or six peripheral, disk florets. These florets lack stamens. Each has one pistil with an inferior ovary and a deeply forked style that curls beyond the floret. In the center of the flower head there are seven or more bisexual disk florets, each with five stamens. The anthers have pointed appendages on the top and are fused into a column around the style, resembling a tiny crown. Both peripheral and central florets have  a pale, greenish yellow corolla and lack a pappus. Flowers generally occur between May and November.1

The fruit is dry, one-seeded and does not split open at maturity. The tiny elliptical seeds are about 3/64 inches (0.1 cm) long.

ground view of tall leafed flower

Flowers occur in complex clusters | Rios trailhead | August 2011

close up of long green leaf

Leaves may be incised into a few short lobes | La Orilla revegetation area | August 2018

close up of yellow small flowers clustered together

Clusters of flower heads | Nature Center | August 2018

Distribution 7,59,89

California mugwort is native to the western United States, from California east into Idaho and Nevada. It is found in low, wet places and upper stream banks in a variety of vegetation types below about 8600 feet (2600 m). It has a limited tolerance for salinity

In the Reserve, mugwort’s fondness for damp spots limits its distribution. A few plants can usually be found along the board walk at the Nature Center and, on the south side of the Reserve, in shady areas west of the freeway. A fairly extensive patch grows in the acacia and eucalyptus forest just west of I-5. In the East Basin, California mugwort has been planted in the revegetation area near La Orilla trailhead.

Classification 2,11,44,49,143

California mugwort is a dicot angiosperm in the sunflower family, the Asteraceae. This is the largest family of vascular plants in the Northern Hemisphere. “Flowers” of Asteraceae are made up of one or both of two types of flowers: symmetrical disk florets and strapped-shaped ray florets. These are crowded onto a common base (receptacle) surrounded by leaf-like phyllaries, and together are often assumed to be a single flower, which we call a flower head. Other familiar Asteraceae that occur in the Reserve includebush sunflower (Encelia californica), goldenbush (Isocoma menziesii), and coyote brush (Baccharis pilularis).48

Species in the genus Artemisia have inconspicuous flower heads; ray florets are absent and disk florets are tiny. The pappus is absent or minute.2 The other Artemisia species in the Reserve are California sagebrush (A. californica), wild tarragon (A. dracunculus) and Palmer’s sagewort (A. palmeri).48

Alternate Scientific Names:

A. compestris, A. vulgaris

Jepson eFlora Taxon Page
long weed looking plant with yellow flowers on ends

Nature Center | August 2011

cluster of small yellow flowers on a branch

A cluster of flower heads | Nature Center | July 2018

Closeup of flower head

One flower head showing curled styles of peripheral disk florets and anther cone of central floret | Nature Center | August 2018


California mugwort has an extensive rhizome system that sends up numerous shoots forming extensive clonal stands.174 The rhizomes also protect the underlying soil from erosion, allowing mugwort to persist along stream banks, road cuts and in other fragile areas.169

close up of branch with small yellow flower pods bunched together

Nature Center | August 2018

small bushel of weeds

Colony from rhizomes | Rios trailhead | August 2018

Bushes growing alongside trail

Rios trailhead | May 2016

Human Uses

Mugwort is often mentioned in modern herbal literature92,432 but the plant referred to is usually the Asian-European species Artemisia vulgare which has become naturalized in some parts of the United States. A. vulgare has a long history in the religious and medicinal beliefs of many cultures.

California mugwort also has an extensive history of use among native Americans. The North American Ethnobotany Database282 lists numerous diverse uses by ten Indian tribes in the western United States. These ranged from treatments for arthritis and bronchitis to ghost repellents. Locally, the Chumash from the shores of the Santa Barbara Channel and offshore islands, gathered the wool of California mugwort leaves into small cones; these were ignited and used to cauterize wounds and treat other ailments.15 Modern Chumash use the leaves as a remedy for poison oak. The Luisaño from northern San Diego and Riverside counties made arrows from mugwort stalks.17,34 In San Diego, the Kumeyaay used a poultice of fresh leaves on ant bites; they made a tea to drink when ill or to bath in for measles.16

Green stems with green leaves

Nature Center | June 2018

small yellow flowers bundled on a branch

Kumeyaay applied leaves to ant bites | Nature Center | August 2018

microscopic view of flower pod side, webbing-like material

Chumash gathered leaf hairs for cauterizing wounds | Nature Center | July 2018

Interesting Facts

There are several theories and variants about the origin of the common name, mugwort. Some believe the first syllable comes from old Anglo-Saxon words “mucg” or “mug” which refer to a midge, or the word “moughte” which refers to a moth or a maggot, and the second syllable from “wyrt” or “wort” which mean root or plant. The name then reflects the past use of one of the mugworts as an insect repellent.24,35,41,92

The second theory comes from Britain, where mugwort was used to flavor beer, before the introduction of hops. In this theory, “mug” refers to the common drinking vessel.41,92 and the name mugwort has a more alcoholic connection.

close up of flowers bunched together on a branch

Nature Center | August 2018

overhead view of plant

Rios trailhead | May 2010

green leaves that are teardrop shaped

Rios trailhead | May 2016

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