Opuntia abjecta Opuntia abjecta Opuntia abjecta is a short cactus, perhaps to 15(25) cm tall. It occurs in the Florida Keys and has been conflated with "O. triacantha". Recent work shows that the two taxa are distinct. In addition to morphological and phylogenetic (DNA) differences, "O. triacantha" occurs in Cuba, whereas "O. abjecta" occurs in Florida. Currently It is Listed as critically by the IUCN Red List. "O. abjecta" grows on humus over limestone or even on bare limestone. Cladodes are typically 2.5 cm long by 4–5 cm long. The cladodes do not shatter, but do deattach from each other with some
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