Western Goldenrod

Euthamia occidentalis

From the boardwalk | September, 2011

In late summer, if you know just where to look along the boardwalk at the Nature Center, you may spot the golden plumes of western goldenrod (Euthamia occidentalis), peeking out between the willows and mule fat. This is one of a few species in the goldenrod tribe that has successfully moved from the east coast and midwest and found a home in California. It is the only one thus far reported from the Reserve.

Western goldenrod is a water loving species, usually found associated with lakes, marshes and stream banks, habitats not common in the Reserve. This patch is probably facilitated by the freshwater run off from the surrounding development that enters the Reserve next to the parking lot and supplies fresh water to the small riparian area.

Over the past decade, this little patch of western goldenrod has been shrinking, This may indicate a decrease in the amount of freshwater input, due either to declining rainfall or more efficient use of garden water in nearby gardens.

Other Common Names:

Western goldentop, Western flat topped goldenrod, Grass-leaf goldenrod

Description 4,8,59,306,399

Western goldenrod is a multiple-stemmed herbaceous perennial plant that spreads from underground rhizomes. Stems above ground are slim and erect, often short-branched above the midpoint. Height may reach six feet, rarely more. Narrow, linear leaves are hairless with smooth margins; they lack petioles and are usually less than four inches (10 cm) in length. Parts of the plant may become resinous. 4,41

Numerous, small flower heads are united into loose, rounded clusters at the ends of slim branches. Each small flower head is .14 to.18 inch (.35 to .45 cm) across, with 15-25 yellow ray florets surrounding 6-15 yellow disk florets on an elongate shingled receptacle with four to five rows of overlapping green-aging-tan phyllaries which are progressively shorter from the inner to the outer. Ray florets are pistillate, disk florets are bisexual. The calyx of both florets is modified into a whirl of white to tan bristles (the pappus). Flowers bloom late summer (late July – early November,7,59 and are said to smell like Acacia.

Fruits are dry and one seeded, narrowly conic, less than 0.2” inch (.46 cm) long with a pale-tan to white, bristly parachute (the mature pappus) that is attached at the wider end and is about the length of the fruit.

A cluster of flower heads | Nature Center boardwalk | September, 2011

Flower heads of disk and ray florets | Nature Center boardwalk | September, 2011

One-seeded fruit | Nature Center boardwalk | October 2021

Distribution 7,59,89,306

Western goldenrod is native to scattered areas across the western United Stated, west to Nebraska, north into southern Canada and south into northern Mexico. It is concentrated below 1000 feet along the west coast of California and in the Central Valley.

Western goldenrod prefers moist habitats, along streams and irrigation ditches, and in meadows and marshlands. It has also been reported from coastal marshes, forests and disturbed areas.

In San Elijo Lagoon Ecological Reserve, I have found only one patch of western goldenrod, this at the Nature Center, at the edge of the willows in the sand wash along the board walk. This patch has been declining in size during the past 10 years. The cause is uncertain; it may indicate changes in the water table or overgrowth by willows and mule fat. Another patch was reported in 1991 along Manchester Ave in the drainage from Mira Costa College. 437


Western goldenrod is a dicot angiosperm in the sunflower family, the Asteraceae 2,11 This is the largest family of vascular plants in the Northern Hemisphere.143 “Flowers” of Asteraceae are made up of one or both of two types of flowers (florets): symmetrical disk florets and strapped-shaped  ray florets. These are crowded onto a common base (receptacle), and together are often assumed to be a single flower, which we call a flower head.11,44,49

Other familiar Asteraceae that occur in the Reserve include bush sunflower (Encelia californica), goldenbush (Isocoma menziesii) and California sagebrush (Artemisia californica).48

For many years, species of Euthamia were placed with the other goldenrods in the genus Solidago.502 Recently, five species were moved to Euthamia, based on DNA sequencing, and on morphological characteristics such as the arrangements of the flower heads in a cluster. 306 Only one species of Euthamia is found in California.2,7

Alternate Scientific Names:

Solidago occidentalis

Jepson eFlora Taxon Page

Nature Center boardwalk | October 2021

A cluster of flower heads | Nature Center boardwalk | September, 2011

Each flower head consists of both ray florets and disk florets | Nature Center boardwalk | September, 2011


Western goldenrod is one of a few species in the Reserve that begin their main bloom in late summer and early fall. This strategy is thought to be a trade-off between adequate moisture for rapid growth and seed production in early spring and reduced competition for pollinating insects in late summer. There is a cost for delayed reproduction: the plant must divert energy from spring reproduction to maintaining active tissue during the summer drought period. It is not a better strategy, it is a different one.

Thus, in late summer into fall, western goldenrod flowers join the yellows of goldenbush and telegraph weed, offset by the lavenders of Del Mar sand aster and twiggy wreath plant, all visited by a wide variety of busy insects.

Patch by the Nature Center boardwalk | September, 2011

Same patch is much smaller by October 2021

Nature Center boardwalk | September, 2011

Human Uses

Species in the goldenrod tribe (Solidago and Euthamia) are known for a wide variety of medicinal uses by native Americans: 282 from treatment for burns, ulcers and wounds to use in basketry, as food and for luck in gambling . Nevertheless, we have found only a single report specifically mentioning western goldenrod: the Ojibwa peoples, used an extract of the root to treat chest pain and lung problems. 533

Leaves were to treat burns and wounds | Nature Center boardwalk | September, 2011

Leaves were used for fevers and diarrhea | Nature Center boardwalk | August 2011

Seeds were used for food | Nature Center boardwalk | October 2021

Interesting Facts 534  

A legend from the new world, tells of an old woman who lived alone in a little hut beside a clear lake. It was said she could talk to the things that lived in the forest and that she could change humans into animals or birds or plants.

One day in late summer, two small girls were wandering along the shore of the lake, gathering flowers and discussing what they would like to be, should the old woman put her spell on them. One had beautiful golden hair; the other had deep blue eyes that looked like stars. Golden hair said she wanted to make everyone who saw her feel happy and cheerful. Her companion said she wanted to stay near her friend. As the sun began to set, the children noticed a little hut by the shore and they ran toward it.

That was a long time ago, and no one has seen the children since, but the next morning, there were two new wildflowers blooming in the meadows and on mountain sides. One was a bright yellow plume that waved in the wind and glowed like gold in the sunshine, and the other was a little starry purple flower. The two are never far apart and they are called Goldenrod and Aster.

Nature Center boardwalk | September, 2011

Del Mar sand aster blooms in the fall with western goldenrod

Nature Center boardwalk | August 2011

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