Opuntia galapageia Hensl.
Galápagos Prickly Pear
This variety of prickly pear cactus is found in the Galápagos Islands, at elevations up to 4921' (1.5 km). Charles Darwin noticed that cactus finches preferred its fruits and flowers, dispersing its seeds. Doves and mockingbirds also eat the fruit. Tortoises and land animals eat the pads.
Plants: A shrubby or tree-like cactus. It may remain low and creeping, or become tree-like, with a woody trunk and reddish brown bark, reaching 8-16' (2.5-5 m) in height. Its habit, armament of joints, and character of its spines are all highly variable. It may form large, sprawling thickets. Stems are a series of fleshy pads up to 15" (37 cm) × 9" (22 cm), covered with evenly spaced clusters of 7 to 28 yellowish-white or brown spines. These spines are soft and flexible instead of rigid.
Flowers: Yellow flowers are up to 3" (8 cm) long.
Fruits: Called “prickly pears,” fruits are large, green, and fleshy. They are approximately ovoid, and usually contain multiple seeds.
Opuntia galapageia on llifle.com
Opuntia galapageia on EOL: the Encyclopedia of Life
Opuntia galapageia on ARKive: Images of Life on Earth
Opuntia galapageia on Wikispecies
Opuntia galapageia on the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species
Opuntia galapageia description by Thomas H. Kent, last updated 12 Oct 2018.