Eschscholzia is a genus of the Papaveraceae family that includes one dozen species of flowering plants. Most plants in this genus are annuals or perennials, and they are slightly toxic. These plants develop cylindrical fruit with tiny seeds and bear flowers that typically close when confronted by clouds. Eschscholzia plants have distinctively wedge-shaped petals and thrive in dry, warm climates.
One well-known species in this genus is Eschscholzia californica, perhaps better known as the California poppy. This plant has renown as the state flower of California in the United States, and is very common in the western United States. Native Americans once utilized this plant for medicinal purposes, and extracts from it can be smoked to activate a slight sedative effect.
Eschscholzia californica is widely recognized as a potentially invasive species within the United States. However, it has been imported to many countries, such as Chile. The introduction to Chile, Argentina, and South Africa is speculated to be intentional for ornamental purposes. In Chile, the seeds of this plant were accidentally mixed with those of another flowering plant, and the rapid spread of the species did not come as a surprise. For unknown reasons, the plants seem to thrive even better in Chile than in its native country. As of 2010, there are no known efforts to control Eschscholzia californica in Chile.
Another species, Eschscholzia ramosa, is a wildflower that is native to the Channel Islands of California. It is an annual herb that has stalks that grow up to 1 foot (0.3 m) high. The poppy flowers are yellow with orange spots. This plant is often confused with its close relative, Eschscholzia elegans. Unlike the California poppy, this species — and most other species in the genus — is not considered potentially invasive.
A much rarer species, Eschscholzia rhombipetala, or the diamond-petaled California poppy, was once deemed extinct in the 1970s as no signs of the plant could be found. In the early 1990s, it was rediscovered growing in a relatively small area of California and in a federally funded California research center. The plant prefers to grow in clay soil that frequently collects fresh puddles of water; this, coupled with the fact that it usually blends in with its surroundings, makes it nearly invisible. As of 2010, it is on the official list of endangered species, though due to past confusion about its continued existence, many people still believe it is already extinct.