Eschscholzia californica Cham.

California Poppy
Papaveraceae (Poppy Family)

California poppy is a somewhat glaucous, freely-branched, erect to spreading annual or perennial growing to 2' tall with leaves that are several times ternately dissected into rounded, lobed segments.  The flowers are solitary on 2-6" long stems and are a showy bright yellow to orange color.  The two sepals are united, forming a hood over the bud as it develops, and then deciduous when the petals open.  The four petals are up to 2" long and open from the erect bud.  The stamens are numerous and surround the single pistil.  There is a torus or ring at the base of the petals, the absence of which signals that you have found Eschscholzia caespitosa, the California collarless poppy, which is a smaller, more yellow flower with petals only 3/4-1" long.  California poppy is found in grassy and open places in many plant communities up to 6500' in much of cismontane California, and can bloom from February to September.  It is exceedingly variable, and is the state flower of California.  This is a species which folds up its petals when the light begins to fail, and sometimes does not open on a cloudy day.  It is often found after burns.

Click here for Latin name derivations: 1) Eschscholzia 2) californica.
Pronunciation: esh-SHOLE-tzee-a ka-li-FOR-ni-ka.
Click here for Botanical Term Meanings.