The true Ombú

Recall ID Challenge #21, which featured a photograph of the massively buttressed trunk of a rubber tree (Ficus elastica) planted more than 200 years ago in Buenos Aires, Argentina and give the name Gran Gomero (meaning “big rubber”). There are many photographs of this tree on the internet, owing to its celebrity status, which allowed more than a few participants to properly guess its identity. Unfortunately, one participant still guessed the wrong answer despite having found an image of the exact same tree due to the tree being incorrectly identified as an Ombú tree (Phytolacca dioica). Unlike the rubber tree, which is native to south and southeast Asia, the Ombú is indigenous to South America and is, in fact, the only “tree” that occurs naturally in the South American Pampas. I place the word tree in parentheses, because this plant—also unlike the rubber tree—is not even really a tree, but rather multi-stemmed shrub (albeit a very large one) in the family Phytolaccaceae (relative of the common pokeweed). Like its North American cousin, the milky sap is laced with toxic compounds that protect it from vertebrate and invertebrate herbivores, and its massive, fire resistant trunks consist of soft water storage tissues arising from enlarged bases. These features are obvious adaptations to life on the Pampas, where rainfall is scarce (10–30 in per year) and fires are frequent.

Ombú (Phytolacca dioica) | Buenos Aires, Argentina

Ombú (Phytolacca dioica) | Buenos Aires, Argentina

While not nearly as spectacular as El Gran Gomero, there is an Ombú growing nearby in the same very plaza adjacent to the Recoleta Cemetery (above photo) that typifies the multi-stemmed, swollen-base appearance that very large specimens assume. It is easy to see how, at least based on superficial appearance, one could mistake El Gran Gomero for an Ombú; however, it also goes to show that one should always be cautious about too quickly accepting what they find on the internet (watch somebody now point out an error in this post!).

Here is another (better) photo of the exact same tree.

Copyright © Ted C. MacRae 2013