Although the leaves and stems of prickly poppy (Argemone munita) resemble those of a a thistle, the large, showy flowers bear no resemblance to thistles. Nor do they belong to the same family. These native plants inhabit dry, open spaces with sandy or gravelly soil and recolonize quickly after fires. Growing as annuals or perennials, prickly poppies are found in Oregon, Idaho, California, Utah, Nevada and Arizona.
Arising from a taproot, the single stem of a prickly poppy is topped by blossoms that can grow to 5 inches in diameter. The plant exudes yellow sap when cut. Each flower has six crinkly white petals surrounding a dense yellow center of up to 250 stamens (male reproductive organs). The pistil (female reproductive organ), formed from 3 to 5 carpels, looks like a dark spot amid the golden yellow stamens. Each sessile (no stalk) leaf is irregularly and deeply divided into lobes with spiny teeth on the tips. Sharp spines cover the leaves and stems giving prickly poppy its common name. Small, black seeds are contained in spine-covered capsules.
Prickly poppies contain alkaloids that are toxic to man and other animals. Toxicity varies with the season. Since ingestion of prickly poppies causes slight to moderate motor activity inhibition or even death in large enough quantities, in my opinion use of this plant for the few medicinal purposes described in the literature seems foolish.
The genus name, Argemone, comes from the Greek and means “white spot (cataract) of the eye”. Members of this genus were purported to cure cataracts. “Armed”, the meaning of munita, refers to the spiny nature of this plant.
Flatbud prickly poppy, chicalote and munite prickly poppy are other colloquial names for A. munita.
These prickly poppy plants were photographed along Lassen County Road A-1 near Eagle Lake CA.