1. Any plant of the genus Argemone having large white or yellow flowers and prickly leaves and stems and pods; chiefly of tropical America
   "The prickly argemone is also known as white thistle";
   - prickly poppy, argemone, devil's fig
    
2. Spiny shrub with silvery-scurfy foliage of alkaline plains of southwestern United States and Mexico
   "white thistle provided natural shelter for desert wildlife";
   - quail bush, quail brush, Atriplex lentiformis

Derived forms: white thistles

Type of: herb, herbaceous plant, saltbush

Part of: genus Argemone

Encyclopedia: White thistle