Opuntia pinkavae Opuntia pinkavae Opuntia pinkavae, common names Bulrush Canyon prickly-pear or Pinkava's pricklypear, is a species of cactus known only from northern Arizona and southern Utah. It grows in sunny locations in grasslands, on the edges of pinyon-juniper woodlands, on sandy or limestone soils. It was named for Dr. Donald Pinkava, professor emeritus at Arizona State University in Tempe. He studied "Opuntia" for many years. The species is one of the smaller members of the group, rarely more than 25 cm (10 inches) tall. Stems are green, flattened, up to 15 cm (6 inches) long. Flowers are magenta with yellow to
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