Plant Image

Yavapai County Native & Naturalized Plants

Amaranthus palmeri - carelessweed

Other Common Names: Palmer's amaranth, pigweed
Plant Form: Forb or Subshrub

Family: Amaranthaceae

line decor
  Home   Plant Communities Plant List Search Forbs and Subshrubs Search Grasses Search Woody Plants Additional Resources About this Website
line decor

Click on Any Image for a Larger View

Patrick Alexander @, Usage Rights: Creative Commons Attribution-ShareAlike (CC BY-SA)
Max Licher @, Usage Rights: Creative Commons Attribution-ShareAlike (CC BY-SA)
Forb Plant Description

Origin: Native   Life Cycle: Annual   Similar Species: Amaranthus retroflexus, Amaranthus hybridus, Amaranthus rudis
General Desc: An erect, tall, summer annual with long panicles of small, green, inconspicuous flowers. It is an aggressive, invasive weed native to the desert regions of the southwest.
Identification notes: Male and female flowers on different plants; sepals of female flowers broadened upward, blade noticeably wider than the base and not fringed with hairs. A long leaf stem distinguishes Amaranthus palmeri from other species.
Height: To 6 feet


Habitat Description: Can occur in non-wetlands and wetlands; roadsides, ditches, fields, arroyos.
Plant Communities: Desert Scrub, Riparian, Disturbed Areas
Elevation: 325 - 3800 feet

Flower Characteristics

Color: Green     Shape: Inconspicuous in elongated clusters     Tubular: N     Flowering Period: Aug - Nov
Description: Female plants have a long main terminal flower head, 1-1/2 feet (or more). The inconspicuous flowers have stiff, sharp bracts that give the panicle a prickly feeling when touched.

Leaf and Stem Characteristics

Leaf Color: Green     Leaf Type: Simple     Leaf Shape: Triangular     Leaf Margin: Smooth     Leaf Attachment: Alternate     Leaves Clasp: N
Hairs: No     Spines: N
Leaf Description: 2 to 8 inches long. The petioles will be as long (or longer) than the leaf blade; leaves are arranged symmetrically around the stem. Stems are erect, branched, and usually reddish. Roots are mostly taproot and reddish in color.

Fruit and Seed Characteristics

Fruit Color: Reddish-brown    
Fruit Type: Achene
Seed Notes: Shiny, reddish-brown in color; tiny, less than 1/16 inch.

  Arizona Cooperative Extension
Yavapai County
840 Rodeo Dr #C
Prescott, AZ 86305
(928) 445-6590
Version 8.0  
Last Updated: Dec 13, 2022
Content Questions/Comments: Email Matt Halldorson  
Legal Disclaimer