Romneya coulteri aka California Tree Poppy

Romneya coulteri, also known as Coulter's Matilija poppy or California tree poppy, is a perennial species of flowering plant in the poppy family Papaveraceae. This plant is native to southern California, USA, and Baja California, Mexico, where it grows in dry canyons in chaparral and coastal sage scrub plant communities, sometimes in areas recently burned. It is a popular ornamental plant, kept for its large, showy flowers. This herbaceous perennial can exceed 2 m (7 ft) in height, with a woody stem growing from a network of rhizomes. The gray-green, waxy-textured leaves are each divided into a few lance-shaped lobes, with the blades growing up to 20 centimeters (7.8 in) long. The inflorescence is a large, solitary flower with six crinkly white petals each up to 10 cm (4 in) long, and a cluster of many yellow stamens at the center. The fruit is a bristly capsule, 3–4 cm (1–2 in) long, containing many tiny seeds. This plant often grows aggressively once planted, spreading clonally by underground rhizomes and appearing several feet away from the original plant. It bears the largest flowers of any species native to California, rivaled only by Hibiscus lasiocarpos. Although nominated for the honor of California state flower in 1890, the California poppy won the title in a landslide. A closely related species, Romneya trichocalyx, has more spiny sepals on the flower buds and overall smaller plant and flowers. Coulter's Matilija Poppy is also a rare houseplant that needs regular watering to thrive. It does best in long-lasting, direct light and should be less than 1 foot from a window. Belonging to the Romneya genus, this plant is native to California to Mexico. In cultivation in the UK, Romneya coulteri and the cultivar ‘White Cloud’ have gained the Royal Horticultural Society’s Award of Garden Merit. The specific epithet coulteri commemorates Thomas Coulter, an Irish botanist and explorer.