This poppy is a perennial whose erect stems are somewhat woody at the base, and may reach 60 cm in height. The leaves resemble those of Eschscholzia, being finely divided into many gray-green linear lobes. The flowers are solitary yellow cups formed from four overlapping petals, 5-7 cm across, vaguely resembling the tulip; the two sepals underneath typically fall away as the flower opens. The numerous stamens are short, with orange anthers. The long thin fruits are also reminiscent of Eschscholzia.
In nature it is typically found at elevations of 1500-2000 meters in the Chihuahuan Desert and south into central Mexico, where it favors rocky habitats, and occurs along roadsides as well.
It is widely cultivated.
The genus is named for English botanist and collector John Hunnemann (1760-1839).