Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Thymophylla acerosa, Pricklyleaf Dogweed

Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora   Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora   Thymophylla acerosa, Pricklyleaf Dogweed, Southwest Desert Flora

Scientific Name: Thymophylla acerosa
Common Name: Pricklyleaf Dogweed
Also Called: Fetid Marigold, Pickleleaf Dogweed, Prickleaf Dogweed, Scrubby Dogweed and Texas Dogweed, (Spanish: Contrayerba, Contra Hierba)
Family: Asteraceae, Sunflower Family
Synonyms: (Dyssodia acerosa)
Status: Native
Duration: Perennial
Size: Small, 4 to 9 inches.
Growth Form: Forb/herb, shrub or subshrub; numerous stems or branches; woody at base; stems covered with dense or scattered hairs (pubescent), or becoming smooth (glabrescent) but rarely completely devoid of surface hairs.
Leaves: Green; mostly opposite; leaves entire, linear, threadlike (filiform), usually needlelike (acerose), not lobed.
Flower Color: Yellow flowers; radiate heads, ray florets yellow, 7 to 9 or more (+12); disk florets numerous, corollas also yellow; fruit is an achene.
Flowering Season: March to October.
Elevation: 3,500 to 6,000 feet or more.
Habitat Preferences: Dry rocky slopes and mesas.
Recorded Range: Pricklyleaf Dogweed is primarily found in the southwestern United States in, AZ, NM, NV, TX and UT. It is also found scattered in northern and north east Mexico. In Arizona it is generally found in the north, central and southern parts of the state as well as Mohave, Graham and Cochise counties.

U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available.

Genus Information: 8 species in Thymophylla, southern and southeast United States. 3 species occur in Arizona. Sonoran Pricklyleaf, Thymophylla concinna, is extremely limited in the United States to Pima County, Arizona and Fiveneedle Pricklyleaf, Thymophylla pentachaeta with 4 varieties.

Comments: Pricklyleaf Dogweed or Fetid Marigold has its major population centers in Arizona, New Mexico and northwest Texas suggesting that this species is more closely aligned with the Chiricahua Desert. An interesting observation as its closest relative Fiveneedle Pricklyleaf, Thymophylla pentachaeta is aligned with the Mojave Desert.

This species is similar to Fiveneedle Pricklyleaf, Thymophylla pentachaeta which is has divided or lobed leaves and is slightly larger. The botanical name definition "acerose" means needle-shaped or sharp referring to the needlelike leaves. As the name "Fetid Marigold" might suggest, Dogweeds often have strong odors, generally more offensive than pleasant.

The photographs above were taken May 08, near Deer Creek, Gila County, Arizona.

Several uses have been identified for Hopi Tea Greenthread including its use as a tea, a stimulant and it was used to coffee. See the complete species account from Native American Ethnobotany, University of Michigan, Dearborn.

Date Completed: 8/16/2014; Updated, 07/26/2015
References:
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database – ITIS search: http://www.itis.gov/servlet/SingleRpt/SingleRpt (accessed 8/16/2014
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, as Dyssodia acerosa.
John L. Strother, FNA | Family List | FNA Vol. 21 | Asteraceae | Thymophylla, Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. (accessed 08/16/2014)
John L. Strother, FNA | Family List | FNA Vol. 21 | Asteraceae | Thymophylla, FNA Vol. 21 Page 238, 240, 241, Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. (accessed 08/16/2014)
SEINet for synonyms, scientific names and recorded geographic locations, http://swbiodiversity.org/seinet/