The Prickly Pear Cactus

The Galapagos Prickly Pear Cactus belongs to the Opuntia genus (Family Cactaceae). This cactus has flat, fleshy pads that look like large, thick leaves. The pads are essentially modified branches or stems that serve a few functions: photosynthesis (as with the leaves of any plant), water storage and flower production. This cactus has large spines that grow from small, wart-like projections called tubercles on the stems. Just above the cluster of regular spines we find glochids, which are thinner spines usually yellow in color and that detach more easily from the pads. Glochids are often a lot more difficult to remove once they are lodged in human skin.

The Prickly pear cactus species found in Galapagos grows on dry, rocky flats and slopes. They have yellow flowers and vary in height from under a foot to up to 7 feet tall. The pads (leaves) of this cactus can vary in length, shape, width and color but always have spines. The fruits of the Galapagos prickly pear cactus are called a “tuna” and it is edible, although guests are not allowed to eat the fruits on a Galapagos cruise. These fruits are rich in soluble fibers.

Land Iguanas on Santa Fe Island, for example, feed primarily on the Prickly Pear cactus fruits and pads. Iguanas often lay for days under a cactus to wait until one of the fruits falls off the tree. They also climb on the trunks of the cacti to reach the pads and bite off pieces of the pads.