Opuntia microdasys Opuntia microdasys Opuntia microdasys (angel's-wings, bunny ears cactus, bunny cactus or polka-dot cactus) is a species of flowering plant in the cactus family Cactaceae, native and endemic to central and northern Mexico. "Opuntia microdasys" forms a dense shrub 40–60 cm tall, occasionally more, composed of pad-like stems 6–15 cm long and 4–12 cm broad. "Opuntia microdasys" has no spines, but instead has numerous white or yellow glochids 2–3 mm long in dense clusters; these glochids are barbed and thinner than the finest human hairs, detaching in large numbers upon the slightest touch. If not removed they will cause considerable skin
Opuntia arenaria strongly deflexed and much shorter. Overall, plants (clumps) of cladodes may be 20–30 cm across and about 4–8 cm tall. Fruits are small, about 2.5 cm. Opuntia arenaria Opuntia arenaria was considered a variety of "O. polyacantha" by many botanists, and is still treated that way in the Flora of North America. However, "O. arenaria" is diploid and "O. polyacantha" is tetraploid. It was described by Engelmann in 1856. "Opuntia arenaria" can grow in soil that is essentially pure sand. It has rhizomes up to 1.5 m long that give rise to above ground shoots with small cladodes that are