(Photograph = Opuntia mojavensis in winter)
Introduction
Opuntia mojavensis is an enigma. The only historical drawing shows 2 spine clusters and an immature fruit. The herbarium sheet (lectotype) also has limited material.
The Details
Britton and Rose reported that the species was imperfectly understood. We observed a plant growing at the summit of Mt Potosi near Las Vegas, NV that may be O. mojavensis. The spines seem similar to those of the the single, imperfect herbarium specimen. The cladodes are round(ish) but sometimes oval or obovate, and the plant is more upright than O. phaeacantha. The original description alluded to the possibility that O. mojavensis could be a form of O. phaeacantha, but it was described as a separate species.
O. mojavensis is larger than O. phaeacantha, and O. mojavensis is more upright. More upright means O. mojavensis is more woody, i.e., the plant has more wood rather than soft tissues. More wood = a different species. The spines are somewhat different.
Possible O. mojavensis was found at about 4,500 on Mt. Potosi in Nevada. The original description suggests that it could occur anywhere west of the Colorado River in the many desert mountains to the west in Nevada and California.
Opuntia mojavensis (Britton and Rose)
