The nomenclatural history of this species is somewhat complicated due to the varieties, as well as its habit of hybridizing with Opuntia phaeacantha.

It differs from Opuntia phaeacantha by being green year round instead of turning reddish purple during winter or dry seasons, as well as having yellow flowers with red centers.

[2] In the Sonoran Desert, terminal pads face predominantly east-west, so as to maximize the absorption of solar radiation during summer rains.

[11] The overall form of Opuntia engelmannii is generally shrubby, with dense clumps up to 3.5 metres (11 ft) high, usually with no apparent trunk.

[13] The Tohono O'odham of the Sonoran Desert in particular classified the fruits by color, time of ripening, and how well they kept in storage.