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 engelmannii (state) to the Tamaulipan matorral in Chihuahua (state), in Mexico. In the Sonoran Desert, terminal pads face predominantly east-west, so as to maximize the absorption of solar radiation during summer rains. Although found occasionally in the Mojave Desert, it tends to be replaced by "Opuntia basilaris", which does not need the summer rain. The overall form of "Opuntia engelmannii" is generally shrubby, with dense clumps up to high, usually with no apparent trunk. The pads are green (rarely blue-green), obovate to round, about 15–30 cm long and 12–20 cm wide. The glochids are yellow initially, then brown with age. Spines