Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

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

Cirsium ochrocentrum, Yellowspine Thistle

Amaranthus albus, Prostrate Pigweed

Amaranthus albus, Prostrate Pigweed, Southwest Desert Flora Amaranthus albus, Prostrate Pigweed, Southwest Desert Flora Amaranthus albus, Prostrate Pigweed, Southwest Desert Flora

Scientific Name: Amaranthus albus
Common Name: Prostrate Pigweed
Also Called: Tumbleweed Pigweed, Pigweed, Pigweed Amaranth, Tumble Pigweed, Tumbleweed, White Pigweed
Family: Amaranthaceae, Pigweed Family
Synonyms: (Amaranthus albus var. pubescens, Amaranthus graecizans subsp. sylvestris, Amaranthus graecizans var. pubescens, Amaranthus pubescens)
Status: Introduced
Duration: Annual
Size: Up to 3 feet or more.
Growth Form: Forb/herb; erect, bushy, spiny, smooth whitish or yellowish stems with multiple branches, plants monecious or dioecious.
Leaves: Light green; lighter or whitish beneath, alternate, stem leaves with longer petioles than leaves on the branches, leaves linear or ovate.
Flower Color: Green, whitish-green or yellow; tiny inconspicuous flowers, flowers subtended by linear stiff bracts, flower consists of 3 sepals (no petals), inflorescence a cyme with spike-like clusters from leaf axils, wind pollinated, seeds brown or black.
Flowering Season: Summer
Elevation: 1,500 to 8,000 feet.

Habitat Preferences: Disturbed habitats, roadsides, open areas, along riparian and agricultural areas.

Recorded Range: Over most of North America including Alaska and Mexico. Throughout most of Arizona. In Canada, Prostrate Pigweed is an ephemeral introduction and not persistently naturalized. It has been introduced in South America, Eurasia, Africa and Australia.

North America & US County Distribution Map for Amaranthus albus.

U.S. Weed Information: Amaranthus albus is listed in: Weeds of the Northeast, Weeds of Nebraska and the Great Plains, Weeds of the United States and Canada, and Weeds of the West. Plants included here may become weedy or invasive.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: Amaranthus albus is on the USDA 2012 National Wetland Plant List as a facultative species, i.e., usually occurs in non-wetlands, but may occur in wetlands.
Threatened/Endangered Information: No data available.

Genus Information: In North America there are 49 species and 49 accepted taxa overall for Amaranthus. Worldwide, The Plant List includes 105 accepted species names and a further 210 scientific names of infraspecific rank for the genus Amaranthus. The genus Amaranthus was published by Carl Linnaeus in 1753.

In the Southwestern United States: Arizona has 19 species of genus, California has 18 species, Nevada has 9 species, New Mexico has 19 species, Texas has 26 species, Utah has 12 species. All data approximate and subject to revision.

Comments: Prostrate Pigweed is common in Arizona. Its seeds which are scattered about are a food source for doves, quail and other birds. The dried plant readily breaks free and is blown around or "tumbled" by the wind thus dispersing the seeds.

In Southwest Desert Flora also see: Fringed Amaranth, Amaranthus fimbriatus and Carelessweed, Amaranthus palmeri.

Species of the genus Amaranthus are generally referred to as "Pigweeds" and some people are allergic to their pollen which can cause hay fever. Prostrate Pigweed seeds are used for food or ground to make bread and cake. See other ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.

Date Profile Completed: 11/13/2014, 07/06/2015
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles.
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 12/27/2019)
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 12/27/2019).
Sergei L. Mosyakin & Kenneth R. Robertson, FNA | Family List | FNA Vol. 4 | Amaranthaceae Amaranthus, FNA Vol. 4 Page 413, 428, 434, 435, Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. (accessed 11/13/2014).
1993, The Jepson Manual, Citation: ttp:// (accessed 11/13/2014)
Wikipedia contributors, 'Amaranth', Wikipedia, The Free Encyclopedia, 22 September 2014, 20:23 UTC, [accessed 13 November 2014]
SEINet for synonyms, scientific names and recorded geographic locations,