The Prickly Pear Cactus or Opuntia includes over 200 species of cacti, all characterized by their paddle-shaped leaves and commonly known as prickly pear cacti. Out of the 200 species that thrive across the Americas, only six are found in the Galapagos Islands:

• Opuntia echios
• Opuntia galapageia
• Opuntia helleri
• Opuntia insularis
• Opuntia saxicola
• Opuntia megasperma

After arriving in the Galapagos, these six species rapidly diversified into 14 different varieties, exemplifying adaptive radiation. Tall varieties flourish on islands inhabited by giant tortoises, while shorter varieties are found on islands where tortoises are absent. Prickly pears are a vital food source for land iguanas, giant tortoises, doves, cactus finches, and mockingbirds, as well as invasive species like goats. They also provide essential nesting habitat for various bird species. The anthers of prickly pears are thigmotactic, meaning they curl over and deposit pollen when touched, allowing for self-pollination. This adaptation enables them to reproduce even in the absence of other cacti nearby.