Subshrubs or shrubs, large, glaucous, from creeping rhizomes; sap clear. Stems herbaceous above base, branching, leafy, sparsely pilose or glabrate. Leaves alternate, petiolate; blade gray-green, 1-2× pinnately deeply lobed; primary lobes 3-5, lanceolate or ovate. Inflorescences terminal, 1-flowered; bracts present. Flowers: sepals 3, distinct; petals 6, white, obovate, crinkled; stamens many; anthers yellow; pistil 7-12-carpellate; ovary oblong to ovoid, 1-locular or incompletely to completely multilocular by placental intrusion; style absent; stigmas 7-12, flattened, coherent proximally, radiate-ascending, velvety. Fruits capsular, oblong to ovoid, bristly, dehiscing from apex. Seeds many, ovoid, 1.3-1.5 mm, aril absent. x = 19.

Distribution

California and nw Mexico (Baja California)

Discussion

Species 2 (2 in the flora).

Both species of Romneya, closely related and sometimes merged, are cultivated widely in warm regions for their showy, white flowers, which are the largest in the family.

Selected References

None.

Lower Taxa

Romneya coulteri, Romneya trichocalyx

Key

1	Calyx glabrous; seeds papillose; petals 6–10 cm; leaves 5–20 cm.	Romneya coulteri
1	Calyx appressed-pubescent; seeds smooth; petals 4–8 cm; leaves 3–10 cm.	Romneya trichocalyx