Tuesday, 19 April 2016

Giant daisy succumbs to Robinson Crusoe's goats


I saw a humming bird in Chile once. It hummed by as I peered into the flower of a Chilean Chilean Bellflower (Lapageria rosea). Both were in the garden of Hotel Antumalal in Pucón where I was staying on my way to see Monkey Puzzle Trees in the shadow of the smoking Villarica Volcano.

Still, enough bragging about humming birds (one), Chilean wild flowers (in a garden) and latent danger (it was weeks since the last eruption...). What I didn't see - in a garden or in the wild - was the Robinson Crusoe Island Cabbage Tree and its humming bird pollinator. Now that would have been a story to tell.

Dendroseris litoralis is not so rare in cultivation but you have to travel to Robinson Crusoe Island in the Juan Fernández Islands archipelago, about 600 kilometres off the coast of Chile, to see it in the wild. This big-leaved daisy has been described as 'amongst the rarest plant species in the world', threatened by habitat distruction and feral goat grazing.



With its large rubbery leaves, the Robinson Crusoe Island Cabbage Tree looks a bit like some of the giant thistles (Sonchus species) on the Canary Islands, having adapted to a similar island environment.  It's a woody, fast-growing plant. This specimen in our nursery grew from a seedling donated just a few years ago by local grower and collector Alistair Watt.


Robinson Crusoe Island is named after the famous Daniel Defoe character who was shipwrecked on an island for 28 years, at first alone and later with his friend Friday. This particular island in the Juan Fernández Islands was where a real life sailor, Alexander Selkirk, was marooned for five years in the early eighteenth century. According to Wikipedia, the Chilean government changed the islands name from Más a Tierra to Robinson Crusoe in 1966, to 'reflect the literary lore associated with the island and to lure tourists'.

Robinson Crusoe Island is home to other botanical oddities, such as the Chonta Palm (Juania australis), and seems to be worth adding to your bucket list if you like botanically bizarre island floras (along with Socotra, Canary, New Caledonia...)

Until recently the Cabbage Tree was reduced only a few individuals on the island but propagation in gardens and, I'm assuming some reintroduction in its native habitat, have tipped the balance a little. However it is still consider critically endangered in the wild.

Although it has been shown that hummingbirds are the most likely pollinator (attracted by its sugary nectar), it doesn't actually need them. Along with about half the world's plants, this particular species of Dendroseris is what we call 'self-compatible'. That is, it can set seed without pollen from another individual. This makes it a perfect plant for gardens but perhaps not adaptable enough in the wild (cross breeding allows the mixing of genes and generally better ability to adapt to change).

In Daniel Defoe's novel, Robinson Crusoe survives with the help of a few crops, his bible and some goats. On Crusoe's namesake island it is the goats that are the undoing of the Cabbage Tree. That and the 800 or so extra humans.


Images: the plant in the Melbourne Gardens nursery, 18 December 2015.

No comments: