California Poppy

Description:

It can grow 5–60 cm tall, with alternately branching glaucous blue-green foliage. The leaves are ternately divided into round, lobed segments. The flowers are solitary on long stems, silky-textured, with four petals, each petal 2–6 cm long and broad; their color ranges from yellow to orange, and flowering is 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.[1] The fruit is a slender, dehiscent capsule 3–9 cm long, which splits in two to release the numerous small black or dark brown seeds. It is perennial in mild parts of its native range, and annual in colder climates; growth is best in full sun and sandy, well-drained, poor soil.

Habitat:

California, extending to Oregon, southern Washington, Nevada, Arizona, New Mexico, and in Mexico in Sonora and northwest Baja California. It grows well in disturbed areas. In addition to being planted for horticulture, revegetation, and highway beautification, it often colonizes along roadsides and other disturbed areas. It is drought-tolerant, self-seeding, and easy to grow in gardens.

Notes:

Because of its beauty and ease of growing, the California poppy was introduced into several regions with similar Mediterranean climates. It is commercially sold and widely naturalized in Australia, and was introduced to South Africa, Chile, and Argentina. In Chile, it was introduced from multiple sources between the mid-19th century and the early 20th century. It appears to have been both intentionally imported as an ornamental garden plant, and accidentally introduced along with alfalfa seed grown in California. Since Chile and California have similar climatic regions and have experienced much agricultural exchange, it is perhaps not surprising that it was introduced to Chile. Once there, its perennial forms spread primarily in human-disturbed environments (Leger and Rice, 2003). Interestingly, the introduced Chilean populations of California poppy appear to be larger and more fecund in their introduced range than in their native range (Leger and Rice, 2003). Introduced populations have been noted to be larger and more reproductively successful than native ones (Elton, 1958), and there has been much speculation as to why. Increase in resource availability, decreased competition, and release from enemy pressure have all been proposed as explanations. One hypothesis is that the resources devoted in the native range to a defense strategy, can in the absence of enemies be devoted to increased growth and reproduction (the EICA Hypothesis, Blossey & Nötzold, 1995). However, this is not the case with introduced populations of E. californica in Chile: the Chilean populations were actually more resistant to Californian caterpillars than the native populations (Leger and Forister, 2005). It is recognized as a potentially invasive species within the United States, although indications of ill effects have been reported for this plant where it has been introduced outside of California. Ironically, it has been displaced in large areas of its original habitat, such as Southern California, by more invasive exotic species, such as mustard or annual grasses. It is not known whether efforts are being undertaken anywhere in its introduced range to control or prevent further spread, nor what methods would be best suited to do so.