Description:

• Annual or biennial herbs, caulescent, from persistent taproots; sap white to orange; stems glaucous, erect, unarmed to prickly
• Leaves sessile or clasping at base, cauline, alternate, glaucous, pinnately lobed or incised with a dentate prickly margin, and often prickly surface, often mottled over veins, glabrous
• Inflorescences terminal, usually 1-flowered, bracteate
• Flowers hypogynous; buds erect
• Sepals 2 or 3, unarmed or prickly, each prickle with conspicuous stiff apical horns; outer surface usually sparsely prickly
• Petals 4-6(-8), in 2 whorls of 3, large, obovate, creamy white or yellow
• Stamens 20-many; filaments filiform
• Ovary of (3)4-6(7) carpels, 1-locular, ovoid to ellipsoid, mostly distinctly bristly, rarely glabrous, placentas often intruding; style short; stigma 3-5(-7)-lobed
• Fruit an erect capsule, armed with needle-like prickles, opening from apex basipetally by 4-6 valves, up to third of total length, rarely almost towards base; valves separating from framework of vascular elements,with remains of persistent style and stigma still attached to vascular framework
• Seeds many, subglobose, sculptured, brown-black, narrowly crested and with a short apical point; embryo larger than in other genera, ± two-thirds of seed length
• x = 14 or 7 (polyploidy)

Nomenclature:

• *Argemone L.
  • Linnaeus: 508 (1753)
  • Linnaeus: 225 (1754)
  • Bentham: 52 (1862)
  • Oliver: 54 (1868)
  • Prain: 130 (1895)
  • Fedde: 105 (1936)
  • Ownbey: 1 (1958)
  • Exell: 180 (1960)
  • Ownbey: 91 (1961)
  • Lucas: 1 (1962)
  • Henderson & Anderson: 144 (1966)
  • Exell & Gonçalves: 1 (1973)
  • Sorarú: 445 (1976)
  • Kadereit: 504 (1993)
  • Lidén: 5 (1995)
  • Ownbey: 314 (1997)

Distribution & Notes:

• Global: Species ± 23, native to North America, the West Indies, Central and South America, 1 species endemic to Hawaiian Islands
• Southern Africa: Species 2 naturalised, widespread in all provinces and countries