Griffiths, Proceedings of the Biological Society of Washington 27: 24, 1914
Holotype; Isotype; Herbarium; Herbarium; Herbarium; Herbarium (aff O. valida); Herbarium (aff O. valida); Herbarium (aff O. valida); Herbarium (aff O. valida)
Original Description
What is Opuntia valida?
Opuntia valida is a handsome prickly pear cactus found in New Mexico, West Texas, and perhaps Arizona. The spination, areoles, and habit of this cactus are distinctive.
Details
O. valida is erect to ascending, widely radiating branched species, with main limbs ascending or horizontal, and sometimes resting on edge under cultivation, but mostly erect to ascending in natural habitat. Mature plants may be 1 m in height and 2 m wide. The cladodes are obovate [sometimes elongate], large, thick, glaucous, slightly blue-green, very broadly pointed or rounded above, commonly 25 by 32 cm or again 25 by 27 cm. Cladodes may be larger on cultivated plants. Areoles are large and ovate, up to 8 mm. The areoles of this Opuntia are brown when new but darken with age. The glochids are scattered throughout the entire areoles with age, but they may be on the upper part in new growth. Glochids are not numerous. Spines (2-5) diverge in all directions.
Flowers are yellow, the fruit is slender.
Ploidy is unknown.
Other Notes
O. valida may have more elongate pads than O. engelmannii, sometimes rhomboid, especially in New Mexico and Texas specimens. In Arizona, pads may be wide obovate and not particularly elongate. Central spines are more prominent in O. valida than O. engelmannii, up to 3 cm long. O. valida seldom (never?) has radials flat against the pad surface. Older O. valida stems become spinier in age as happens with O. chlorotica chlorotica. Fruit is more slender and typically ripens sooner in O. valida than O. engelmannii. Spines are almost always cream-colored in O. valida with a dark chocolate base; they are more uniform than in the Engelmann Opuntia. Compared to O. engelmannii, O. valida has larger areoles with long stout spreading spines that are angular in cross section. The glochids in face areoles are irregular and mixed in sizes, usually rather long in at least edge areoles. Spines on old stems increase in numbers. See a table comparing O. engelmannii with O. valida.