Eschscholzia

Herbs, annual or perennial, scapose or caulescent, from taproots; sap colorless or clear orange. Stems leafy. Leaves alternate, basal and sometimes cauline, petiolate; blade 1-4× pinnately deeply lobed, lobes of each order usually 3; ultimate lobes narrow. Inflorescences terminal, cymose with bracts present, or 1-flowered. Flowers: receptacle dilated, forming cup beneath calyx, sometimes with free rim; perianth and androecium perigynous; sepals 2, connate, calyptrate, deciduous as unit; petals 4, rarely more (doubled flowers), obovate to obcuneate, with satin sheen from microscopic linear grooves; stamens 12-many; pistil 2-carpellate; ovary 1-locular; style absent; stigmas 4-8, spreading, linear. Fruits capsular, cylindric, 2-valved, dehiscing from base along placentas, often explosively. Seeds many, tan, brown, or black, spheric to ovoid, reticulate, ridged and burlike, or pitted, aril absent. x = 6, 7.

Distribution

w North America (United States), nw Mexico.

Discussion

Species 12 (10 in the flora).

Eschscholzia species are introduced from cultivation elsewhere in warm-temperate regions worldwide.

Selected References

Clark, C. and J. A. Jernstedt. 1978. Systematic studies of Eschscholzia (Papaveraceae). II. Seed coat microsculpturing. Syst. Bot. 3: 386-402.

Ernst, W. R. 1964b. The genus Eschscholzia in the south Coast Ranges of California. Madroño 17: 281-294.

Greene, E. L. 1905b. Revision of Eschscholtzia. Pittonia 5: 205-308.

Lewis, H. and R. Snow. 1951. A cytotaxonomic approach to Eschscholzia. Madroño 11: 141-143.

Lower Taxa

Eschscholzia caespitosa, Eschscholzia californica, Eschscholzia glyptosperma, Eschscholzia hypecoides, Eschscholzia lemmonii, Eschscholzia lobbii, Eschscholzia minutiflora, Eschscholzia parishii, Eschscholzia ramosa, Eschscholzia rhombipetala

Key

1	Receptacular cup with spreading free rim.	Eschscholzia californica
1	Receptacular cup without spreading free rim.	> 2
2	Plants scapose; ultimate leaf lobes acute; petals yellow; calyx glabrous.	> 3
2	Plants caulescent, with flowers borne on leafy stems (not readily apparent in young plants); ultimate leaf lobes acute or obtuse; petals yellow or orange; calyx glabrous or pubescent.	> 4
3	Seeds burlike with raised ridges; petals 12 mm or shorter; California (Great Central Valley, Sierra Nevada foothills).	Eschscholzia lobbii
3	Seeds minutely pitted, not burlike; petals usually 12 mm or longer; California, Arizona, Nevada, and Utah (Mojave and Sonoran deserts).	Eschscholzia glyptosperma
4	Calyx pubescent; buds nodding; leaf blades sparsely pubescent.	> 5
4	Calyx glabrous; buds nodding or erect; leaf blades essentially glabrous, never consistently pubescent.	> 6
5	Petals orange or deep yellow throughout, 15–40 mm; receptacles broader than 1.5 mm.	Eschscholzia lemmonii
5	Petals yellow, sometimes with orange spot at base, 10–20 mm; receptacles narrower than 1.5 mm.	Eschscholzia hypecoides
6	Older buds nodding.	> 7
6	Older buds erect.	> 8
7	Leaf blades bright green or yellow-green, terminal lobes slender, acute.	Eschscholzia parishii
7	Leaf blades grayish or bluish green, terminal lobes broadened at apex, usually obtuse.	Eschscholzia minutiflora
8	Receptacle somewhat swollen and translucent distally, usually broader than 2 mm.	> 9
8	Receptacle strictly obconic, not translucent distally, narrower than 2.5 mm.	> 10
9	Petals (15–)20 mm or more, orange or deep yellow; California (Kern County).	Eschscholzia lemmonii
9	Petals 15 mm or less, yellow; inland California Coast Ranges.	Eschscholzia rhombipetala
10	Flower buds blunt or rounded short-acuminate, tip less than 1/4 length of bud; ultimate leaf lobes elongate, giving diffuse appearance; California Channel Islands.	Eschscholzia ramosa
10	Flower buds apiculate-acuminate, tip usually more than 1/4 length of bud; ultimate leaf lobes short, giving compact appearance; California and Oregon mainland foothills.	Eschscholzia caespitosa