Romneya is a small genus of two species of flowering perennial subshrubs in the poppy family (Papaveraceae). Commonly called Matilija poppies, bush poppies, or tree poppies — and colloquially the "fried egg flower" for their vivid yellow stamens against white petals — they are native to chaparral and coastal scrub habitats of Southern California and Baja California.
Plants grow to around 2.5 metres (8 ft) tall with woody stems and silvery-green, deeply lobed leaves fringed with fine hairs. Their flowers, produced in late spring and summer, are the largest of any member of the poppy family, reaching up to 13 cm (5 in) across. The thin white petals have a distinctive crepe-like, satiny texture, encircling a dense central boss of golden stamens.
The two species — Romneya coulteri (Coulter's Matilija poppy) and Romneya trichocalyx (Bristly Matilija poppy) — are considered separate species in most modern treatments, though some authorities treat R. trichocalyx as a variety of R. coulteri.
In the wild, Romneya are classic fire-following plants: smoke triggers germination, and populations are most abundant after burns in coastal scrub and chaparral. Once established, their spreading rhizomes make them difficult to remove, and on slopes they serve as effective soil binders against erosion.
Etymology
The genus Romneya was named by botanist William Harvey in honour of John Thomas Romney Robinson, an Irish astronomer. The first described species, R. coulteri, further commemorates Romney Robinson's close friend, the Irish botanist Thomas Coulter, who collected the plant in California.
Distribution
Romneya is native to chaparral and coastal scrub habitats in Southern California and Baja California, Mexico. Both species are found in similar arid to semi-arid foothill and canyon environments along the Pacific coast.
Ecology
Romneya species are quintessential fire followers: seeds require smoke cues to break dormancy, and plants regenerate vigorously from rhizomes after fire events in chaparral. They are most frequently encountered in recently burned areas, though they also persist in unburned coastal scrub. On hillsides, their extensive root systems help bind soil and resist erosion.
Cultivation
Romneya thrive in a warm, sunny position with freely draining, relatively fertile soil — traditionally grown against a south-facing wall. They are notoriously slow to establish but spread aggressively once settled and are very difficult to eradicate. They are drought-tolerant once established, which suits Mediterranean-climate gardens.
Cultural Uses
Matilija poppies were used medicinally by the Chumash people of California to treat skin ailments, gum problems, and stomach aches. The common name "Matilija" is said to derive from a Chumash leader, Chief Matilija.
