Trunk buds of the Galapagos prickly pear (Opuntia sp.) on Isabela, Galapagos Islands, Ecuador

Here you can see the remaining buds on the trunk of a Galapagos Opuntia. Each bud is still an active meristem, thus as the cactus ages it continues to grow more and more spines on each bud, such that the buds on the trunk are heavily armored compared with the pads, or cladodes, up near the top of the plant. This image also allows you to see the detail of the bark and highly lignized, or woody, nature of the Galapagos Opuntia tree. In the adjacent photo in particular you can see where two different cladodes (pads) meet and are stacked on top of one another, which provides evidence to the fact that Galapagos Opuntia trees do not form trunks in same way that familar trees like pines, palms, pecans do, but instead grow new cladodes and adapt each cladode branch in a vertical column into a new trunk segment.


For more discussion on why Opuntia of the Galapagos are so neat, and their relationship with the endemic giant tortoises, see this image:


For a discussion on why I find Opuntia so neat morphologically, developmentally, and functionally: see this image:

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Taken on June 4, 2011