"Near the Guardia we find the southern limit of two European plants, now become extraordinarily common... the cardoon (Cynara cardunculus) has a far wider range: it occurs in these latitudes on both sites of the Cardillera, across the continent. I saw it in unfrequented spots in Chile, Entre Rios, and Banda Oriental. In the latter country alone, very many (probably several hundred) square miles are covered by one mass of these prickly plants, and are impenetrable by man or beat. Over the undulating plains, where these great beds occur, nothing else can now live." Charles Darwin, Voyage of the Beagle
The giant thistle is a nasty bugger; native to Europe and found globally, making pastures completely unusable. Here is speaking of the plains and pastures outside Buenos Aires.
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Field trip today to Merrill Creek then met my sister at Hot Dog Johnny's. A very nice day.
Fascinating. I had not realized that cardoons were an invasive. It would be interesting to explore the genetic origin of the invasives. Are they globe artichokes or leafy cardoons that escaped domestication, or are they directly descended from the wild European varieties? The most recent study I could find (Gatto et al "Population structure of Cynara cardunculus complex and the origin of the conspecific crops artichoke and cardoon" Annals of Botany 2013) does not go there. Here is the money line from the article:
ReplyDeleteIn the second scenario, the eastern wild cardoon represents the only original wild form, from which the glove artichoke and the cultivated cardoon originated; the leafy cardoon would have reverted to feral forms, giving rise to the so-called western wild cardoon. In our opinion, this latter hypothesis, which is the most parsimonious one, seems the most plausible, also given the geographic distribution of the species.