General: Flatbud Pricklypoppy (Argemone munita) is a perennial forb with very large (to 5 inches across), flat, flowers. The petals are white and about 2 inches long, and the center is broad and bright yellow, with 150–250 stamens. The leaves are covered with prickles, and the upper and lower surfaces are about equally prickly. The fruit is about 35–55 mm long, and the seeds are 2–2.5 mm long. The sap is yellow.

Stamens 150–250, but count by quarter = 40-60. Only needs to be more than 30/quarter to rule out Mojave Pricklypoppy, which only has 25-30/quarter.

Flatbud Pricklypoppy is a fairly common component of desert and lower montane vegetation communities in the Lower Sonoran (Creosote-Bursage Flats) and Upper Sonoran (Mojave Desert Scrub and Pinyon-Juniper Woodland) life zones.

Along roadsides in the deserts and mountains north of Las Vegas, the large, white flowers often look like squares of toilet paper blowing in the wind.

Family: Poppy (Papaveraceae).

Other Names: Prickly Poppy, Prickly-poppy.

Plant Form: Basal leaves and an upright flowering stalk.

Height: Flowing stalk to about 2-1/2 feet.

Stems: Single, with leaves.

Leaves: Dissected, crinkly, and covered with spines. Leaves mostly prickly on margins and on the veins, about equally prickly on the upper and lower surface.

Flowers: Blooms late spring and early summer. Inflorescence: solitary flowers at the tips of branches. Flowers: sepals prickly; petals 4, white, crinkled, to 1-1/2 inches long; stamens many (150–250), yellow, short.

Stamens 150–250, but count by quarter (40-60). There only needs to be more than 30/quarter to rule out Mojave Pricklypoppy, which only has 25-30/quarter.

Seeds: Fruit: spine-covered capsule, 35–55 mm in length. Seeds: small, black.

Habitat: Dry, well-drained sandy, gravelly, and rocky soils on upper bajadas and moderate slopes in the lower mountains.

Elevation: About 200 to 10,000 feet.

Distribution: Mojave Desert (Southern California, southern Nevada, western Arizona).

Comments: The common name comes from the stout spines on the stems, leaves, and seed pods.