Canary Islands.
Euphorbia bourgeana (tree Euphorbia) is an shrub in the Euphorbiaceae that is native to the Canary islands. It grows primarily in subtropical climates and is sensitive to frost. This species is considered threatened in its native range because of its highly restricted restricted native range on Tenerife and La Gomera islands and threats due to human disturbance. Recently, E. lambii, growing only on La Gomera, was synonymized into E. bourgeana. Tree Euphorbia can grow 6-10' in height and is a charismatic ornamental that has been cultivated and popularized for its attractive stature and foliage. It has a thick gray-colored main trunk. Lower stems are mostly leafless and spreading to erect, with terminal "pom pom"-like clusters of 6-inch-long blue-green green leaves. Plants flower in spring with showy terminal inflorescences that include greenish-yellow bracts and small green flowers. All parts of the plant are poisonous.
Currently sold as an ornamental where it is able to grow and more broadly as a house plant. San Marcos Growers has been growing the species continuously since 1994. The specific epithet of one of the synonymized species with E. bourgeana (E. lambii) was named after a British nurseryman in 1960. We can therefore presume that it was introduced into the nursery trade around that time.