Size: 1 to 3 feet (30-91 cm) or more 3 ½ feet (107 cm)
Growth Form:Subshrub, forb/herb; plants upright (erect), or spreading outward (ascending); multiple stems (25 plus); older plants woody; plants generally without surface ornamentation; in coldest areas stems freeze-back to crown.
Leaves: Light green, dull-green; leaves arranged alternately along stems; leaves narrowly linear, about 2 inches (5 cm).
Flower Color: Yellow, golden yellow; many floral heads made up of diskflorets only; small heads in cluster of 25 or more on tips of stems, fruit is a cypsela.
Flowering Season: June or July to September or October particularly if summer rainfall is adequate.
Elevation: 1,500 to 5,000 feet (457-1,524 m)
Habitat Preferences: Often in Creosote (Larrea) and Mesquite (Prosopis) communities. mesas and plains with saline, sandy, clay or alkaline soils, common along roadsides.
Recorded Range: In the United States, Southern Goldenbush is limited in distribution to the southwestern states of AZ, CO, NM and TX. It is also native to Baja California and northern Mexico in Sonora, Chihuahua, Coahuila, Nuevo León. Southern Goldenbush is found primarily in Arizona and New Mexico with decent populations in western Texas.
North America species range map for Southern Goldenbush, Isocoma pluriflora:
North American range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
Click image for full size map
Genus Information: In North America there are 11 species and 11 accepted taxa overall for Isocoma. Worldwide, The Plant List includes 15 accepted species names and a further 44 scientific names of infraspecific rank for Isocoma.
In the Southwestern United States: Arizona has 5 species of Isocoma, California, Utah and Texas each have 3 species, Nevada has 1 species and New Mexico has 4 species. Data approximate and subject to revision.
Comments: Southern Goldenbush is another of the fall blooming yellow daisies that were formerly included in the genus Haplopappus and/or Aplopappus. Southern Burroweed is similar in appearance to Burroweed, Isocoma tenuisecta, and may superficially resemble several species of Rabbitbrush and Goldenweed.
Southern Goldenbush, Isocoma pluriflora, is believed to cause “trembles”in livestock and “milk sickness” in humans. It is another indicator species of over grazed rangeland. Ranchers attempt to control and limit dense stands of this and other similar species because its presence reduces more desirable browse species.
The flowers, seeds and plants may be visited by hummingbirds and/or small mammals including rodents in search of food, nectar, shelter and protection through cover.
Beneficial Value to Butterflies, Bees and Insects
Southern Goldenbush, Isocoma pluriflora, brightly colored flowers and plants are visited by butterflies, moths and other insects in search of food, nectar or shelter.
The genus “Isocoma” (Isoco'ma:) is from the Greek meaning “an equal hair-tuft,” and referring to the flowers.