By mid summer, clumps of prickly poppies are abundant along the Colorado Front Range, their large white flowers shimmering above ranchlands and dry riverbeds of the High Plains, along country roads and on disturbed meadows of the Piedmont and lower foothills. Protected by spines on their foliage (hence the nickname thistle poppy) and thick, noxious sap in their stems, these open country wildflowers are generally avoided by grazing livestock and wild herbivores.
Represented by 15 species across the U.S., prickly poppies favor dry sandy soil and are most common across the Southern Plains and Desert Southwest. Their large flowers, up to 4 inches across, possess petals that have the appearance and texture of wrinkled paper; in most species they are white while pink or purplish petals occur in some regions. The central dome of stamens is bright yellow or reddish in color, drawing a wide variety of insect pollinators. Seeds of the prickly poppy, which are rather large, have a high oil content and are favored by ground feeding birds, such as pheasants, quail and doves, and small mammals.
The abundance of this wildflower in dry, hot regions of the country is due, in part, to its long tap root that reaches moisture deep within the soil. Despite its poisonous sap, various components of the prickly poppy have been used for medicinal purposes by Native Americans. For the rest of us, their showy flowers, often adorning a dry, stark landscape, are reason enough to appreciate these plants.