Segment surface and spine variation
In the original description, Opuntia lubrica has low, ascending, spreading branches. Segments range from almost round to obovate, usually about 15 × 20 cm, intensely green and glossy. A finely papillose surface is visible under a lens. Griffiths described fruits with red skin, red flesh and a distinctly sour taste. [Griffiths 1910, p. 169]
In young areoles, glochids form a crescent-shaped tuft in the upper part. On two- to four-year-old segments, their number increased until they filled the areole. Expansion of areolar tissue produced short raised structures. Large spines were variable. They almost disappeared on some segments, while becoming more numerous on others, especially as the plant aged. [Griffiths 1910, p. 169]
Name and historical material
The 1910 description combines observations from near Alonzo in Mexico and from plants propagated from segments. The author noted a habit similar to Opuntia microdasys, while distinguishing its more massive, glossy segments. POWO currently accepts O. lubrica as a distinct species from San Luis Potosí and gives a proposed hybrid origin, marked with a question mark, involving O. engelmannii var. cacanapa and O. microdasys. [Griffiths 1910, p. 169] [2-WWW]