Description:

• An erect or sprawling, glabrous, glaucous annual or perennial herb with a thick taproot; sap colourless or clear orange
• Leaves basal and sometimes cauline, multifid or rarely linear, petiolate
• Inflorescences terminal, usually 1-flowered, bracteate
• Flowers perigynous, long-pedunculate
• Receptacle concave, expanded, forming cup beneath calyx, sometimes with conspicuous spreading rim; perianth and androecium perigynous
• Sepals 2, connate into a narrow conical, acuminate, circumscissile cap or calyptra, deciduous as a unit
• Petals 4, obovate to obcuneate, golden-yellow, orange or white
• Stamens 12-many, often adhering to base of petals
• Ovary of 2 carpels, 1-locular, linear, glabrous; style 0; stigmas sessile, 4-8, spreading, linear
• Fruit a capsule, cylindrical, with 10 conspicuous longitudinal ribs, 2-valved, dehiscing from base along placentas, often explosively
• Seeds many, spherical to ellipsoid to obovoid; testa grey-brown, or black, reticulate, ridged and bur-like, or pitted
• x = 6 (aneuploids, polyploidy)

Nomenclature:

• *Eschscholzia Cham.
  • Chamisso: 73 (1820)
  • Chamisso & Schlechtendal: 553 (1826)
  • Bentham: 54 (1862)
  • Meikle: 85 (1977)
  • Kadereit: 503 (1993)
  • Lidén: 11 (1995)
  • Clark: 308 (1997)
• Petromecon Greene
  • Greene: 293 (1905)

Distribution & Notes:

• Global: Species ± 12; in SW North America and North Mexico; some species cultivated as ornamentals and naturalised elsewhere
• Southern Africa: Species 1, naturalised: *Eschscholzia californica Cham. (California Poppy), recorded as a troublesome weed in the Western Cape