Engelmann & Bigelow, Proceedings of the American Academy of Arts and Sciences 3: 293, 1856/1857
Herbarium; Herbarium; Herbarium; Herbarium; Herbarium (submitted as O. phaeacantha major); Herbarium (submitted as O. phaeacantha brunnea); Herbarium; Herbarium; Herbarium; Drawing (Bigelow, J.M., The Botany of the Expedition, 1856, plate IX No. 1-5)
From Powell and Weedin, 2004, page 166:
Opuntia camanchica is a cactus similar in habit to O. phaeacantha, but it is a woodier plant (it has more substantial supportive tissues in its stems). Thus, under comparable conditions, it grows into a taller prickly pear than O. phaeacantha and remains more erect in winter. Also, the sprawling stems of this Opuntia are stiffer than those of O. phaeacantha. The plants are usually less than 70 cm tall. There is much variation in spine number and color (pale, red, white, black, brown, purplish), which is in contrast to O. phaeacantha, which often (not always) has pale spines on the sides of pads. The spines are stout and especially prominent on distal areoles where there may be 4(6) that diverge in several directions. Spines on this Opuntia may have slight curvature.
Flowers are yellow with red centers, 5-7 cm long and wide—often opening less widely than those of O. phaeacantha or O. dulcis. Filaments are 1.5-1.7 cm long and wide and cream colored. Anthers are yellow and about 2 mm long. The style is cream, about 2 cm long, with cream-colored, green, or dark green lobes. The pericarpel is 3-5 cm long with scattered areoles with no spines, except perhaps a few small spines in distal areoles. This Opuntia has pretty flowers because of the red centers, which may be strawberry red.
Red or cherry-red fruits are 3.7-5(-6.7) cm long, 2.3 to 3.3 cm wide and typically have a deep umbilicus. The fruits are spineless except they may have 1-2 spines near the rim. There are relatively few areoles. Fruit pulp is green and juice is clear, but the juice is not sweet and is not abundant. The rind may be colorless. Alternately, fruits may have a reddish pulp and abundant juice. Thus the fruits may vary somewhat on this Opuntia. The seeds are 4 to 5 mm in diameter, irregularly discoid with a broad hilar notch and a prominent aril that is 0.5 mm wide (or more).
Opuntia camanchica is another Opuntia often lumped into O. phaeacantha. The two are different Opuntia species even through they are related. O. camanchica is often a taller plant because it is woodier and can support taller upright branches. O. camanchica may spread to 1.0 to 1.2 m across in a mound, or it may be more irregular and semi-prostrate and sprawling. The areoles are relatively far apart and the pads are thickish by comparison with O. phaeacantha. The often circular-appearing cladodes and stout spines make this Opuntia distinct throughout its range even while spines can vary in coloration or length. O. camanchica grows throughout much of NM and western TX and is also found in AZ, CA, and UT. Read the original description. O. camanchica is hexaploid.