Reference

D. Frias, Roberto Godoy, P. Iturra, S. Koref-Santibánez, J. Navarro, N. Pacheco, G.L. Stebbins (1974/1975): Polymorphism and Geographie Variation of Flower Color in Chilean Populations of Eschscholzia californica – Österreichische Botanische Zeitschrift = Plant Systematics and Evolution – 123: 185 - 198.