Last spring while driving from Illinois to Arizona I began to notice a peculiar plant along the highways. Starting in central Oklahoma what looked like thistles began to appear, but rather than the typical purplish-red star-burst thistle flowers, these plants had large flowers with papery white petals. I eventually learned that these prickly plants were in the genus Argemone, and that they are commonly known as Prickly Poppies.
The species I’ve become familiar with here in Arizona is Argemone pleiacantha, the Arizona or Southwestern Prickly Poppy. It is common in overgrazed rangeland and in other disturbed sites such as roadsides.
One day last month I happened to be hiking through some BLM grassland in the shadow of the Dragoon Mountains. The leased range-land didn’t seem too healthy. The remaining grass was mostly a species which cattle disdain, possibly because of the insidious augur-like seeds which seemed to delight in burrowing into socks. I encountered several withered prickly poppies in that stretch of level grassland, as cattle don’t like that plant either. The Argemone seedpods were open and I had my first encounter with the seeds. I knelt down, split open a few pods and examined the contents.
Prickly Poppies are in the Poppy Family (the Papaveraceae), so I wasn’t surprised to see that the seeds looked like the familiar culinary poppy seeds from plants in the genus Papaver. Argemone seeds are about twice as large, though, and have an interesting surface texture. Here’s a shot of a pod with its seeds spilled out into my palm, which bears abrasions from a struggle with an enormous thicket of thorny “Wait-a-minute” acacia shrubs. Cattle avoid those wicked shrubs too!
A closer view of the seeds, which taste like commercial poppy seeds:
It’s easy to ignore common roadside weeds, but we may as well get used to them as people and roads proliferate unchecked. I like to see rare native plants as well as the next amateur botanist, but I also enjoy the neglected but ecologically adaptable plants as well!