Eschscholzia californica (California poppy, Californian poppy, golden poppy, California sunlight, cup of gold) is a species of flowering plant in the family Papaveraceae, native to the United States and Mexico, and the official state flower of California.
It is a perennial or annual growing to 5–60 in (13–152 cm) tall, with alternately branching glaucous blue-green foliage. The leaves are alternately divided into round, lobed segments. The flowers are solitary on long stems, silky-textured, with four petals, each petal 2 to 6 cm (0.79 to 2.36 in) long and broad; flower color ranges from yellow to orange, with flowering from February to September. The petals close at night or in cold, windy weather and open again the following morning, although they may remain closed in cloudy weather. The fruit is a slender, dehiscent capsule 3 to 9 cm (1.2 to 3.5 in) long, which splits in two to release the numerous small black or dark brown seeds. It survives mild winters in its native range, dying completely in colder climates.