Sonchus brassicifolius, synonym Dendroseris litoralis, is a species of flowering plant in the daisy and sunflower family Asteraceae. It is a small evergreen tree species known as the cabbage tree. It is endemic to the Juan Fernández Islands, which lie in the southeast Pacific, off the west coast of Chile. It is native only to the tiny, volcanic Robinson Crusoe Island, home of the famed Juania australis and many other endemic plants. The species is threatened by habitat loss and has been brought back from the brink of extinction. It had been reduced to only a few individuals by feral goats on the island, and is still considered critically endangered.
Younger trunks of Sonchus brassicifolius are ringed with pale leaf scars and distinctive rubbery, leathery leaves up to 18inches long. It grows into a small, gnarled tree with several somewhat palm-like crowns of very large, ovate leaves on whitish, green-spotted leaf stalks and pendent inflorescences of bright orange, tassel-like 'flowers' (capitula). It is easy to cultivate and enjoys a cool, humid climate. It is hardy to light freezes and California coastal conditions.
The species was first described in 1921 by Carl Skottsberg as Dendroseris litoralis. The genus Dendroseris was considered endemic to the Juan Fernández Islands. In 2012, based on molecular phylogenetic evidence, it was shown that Dendroseris was embedded within the genus Sonchus, and all its species were transferred to that genus, with Dendroseris reduced to a subgenus.[1] As the combination Sonchus litoralis had already been used for a different species, the replacement name Sonchus brassicifolius was published.[1] [2]
The very large leaves are edible and formed part of the diet of voluntary castaway Alexander Selkirk - the possible inspiration for Daniel Defoe's character Robinson Crusoe - during his sojourn on one of the Juan Fernandez Islands.[3] [4]
The capitula with their large orange corollas are hummingbird pollinated. The nectar composition of Sonchus brassicifolius has large quantities of sucrose (73%), 15% fructose and 10.9% glucose.[5]