Southwestern Prickly Poppy (Argemone pleiacantha)

Southwestern Prickly Popy
Argemone pleiacantha

Family: Papaveraceae

These prickly, thistle-like perennials grow in warm weather and bloom in summer into fall. They may go dormant or need to at least be cut back occasionally to look good. Plants have white flowers with yellow centers, resembling a fried egg. Prickly capsules with small black seeds follow the flowers. Plants can grow to 4’ tall when blooming, often found shorter if they are in drier, tougher conditions.

Full to part sun, moderate water with good drainage. Plants hardiness isn’t well-known but they grow in some cold places in our region, and probably can go down below 0°F.

Prickly poppies have a solid history of herbal use and cultivation. They have been studied in research laboratories for several of their potential pharmaceutical effects. Argemone pleiacantha and other species of the Argemone genus have been shown to have a variety of medicinal properties, including anti-inflammatory, analgesic, antibiotic, antimalarial, and anti-tumor effects.

Photo by Sue Carnahan, SEINET
Argemone pleiacantha on iNaturalist

This species is pollinated by a variety of insects, including bees, flies, beetles, and butterflies. Larval host for some moth species:

Neoterpes ephelidaria
Sicya pergilvaria
Platynota labiosana
Trichoplusia ni

There are 17 species of Argemone in Arizona (25 native to the Americas including Hawaii), this is the most common species. Argemone from Greek argemos, a white spot (cataract) on the eye, what it was supposed to cure, pleiacantha is from Greek pleios, many, more than one and akantha, thorn.

Found on dry gravelly soil, foothills and mountain valleys from 2,500-7,500 ft. in Arizona, New Mexico, and in Mexico in Sonora and Chihuahua.