Opuntia microdasys rufida is a species of cactus native to Mexico. It is a small, clumping cactus that can grow up to 1 foot (30 cm) tall and 2 feet (60 cm) wide. The plant has flat, round pads that are covered in small, golden spines and fuzzy, reddish-brown dots. The dots are actually clusters of tiny hairs called glochids, which can irritate the skin upon contact.