About Argemone pleiacantha Greene
Argemone pleiacantha, commonly called the southwestern prickly poppy, is a flowering plant species in the poppy family. It is native to Arizona and New Mexico in the United States, and Chihuahua and Sonora in Mexico, where it grows in dry woodlands and on foothill and mountain slopes. It is an annual or perennial herb that produces branching, erect stems that can reach up to 1.5 meters in height. The entire plant is covered in prickles, often densely. Its blue-green leaves are divided into sharp, tooth-shaped lobes. The flower buds grow up to 2 centimeters long and are covered in prickles. When open, the flowers are showy with white petals, and can reach up to 16 centimeters wide. The fruit is a prickly capsule that grows up to 4.5 centimeters long. There are two accepted subspecies of this plant. A. p. subspecies pleiacantha is the only subspecies found in Mexico. A. p. subspecies ambigua is endemic to Arizona. The Sacramento prickly poppy was traditionally classified as a third subspecies, A. p. ssp. pinnatisecta, but has recently been reclassified as a separate full species based on genetic analysis. This separate rare species is found only on the western slope of New Mexico's Sacramento Mountains, and it is a federally listed endangered species in the United States.
