Engelmann. 1856. Proceedings of the American Academy of Arts and Sciences 3: 307
What is Cylindropuntia bigelovii?
Cylindropuntia bigelovii is a cholla found in the Mojave and Sonoran deserts of California, Arizona, Nevada, and Baja and Sonora, Mexico. It is a tree or shrub growing to 2 m tall.
C. bigelovii occurs on sandy flats, gravelly to rocky washes, bajadas, and hillsides from 300 to 900 m elevation. The terminal stem segments are very easily detatched–hence the common name “jumping cholla”. The stems are 4 to 18 cm long by 2 to 5.5cm wide with 8 to 15 spines per areole. The spines are yellow, aging brown, with white to pale yellow sheaths. The spines are dense and obscure the stem. The flowers are pale green to whitish, sometimes with red tips. The filaments are green with orange anthers. The style and stigma are light to dark green. The fruit is yellow, fleshy-leathery, and becomes spineless over time.
Cylindropuntia bigelovii is mainly triploid (2n = 33); however, several diploid chromosome counts have also been reported. Organisms with an odd number of chromosomes cannot undergo normal meiosis and must, therefore, depend on clonal forms of reproduction. The occasional production of diploid individuals in such species is therefore of the evolutionary importance for providing genetic diversity and environmental adaptability.
Cylindropuntia bigelovii hybridizes with Cylindropuntia acanthocarpa var. major (C. ×campii). It has been widely reported, including in the Flora of North America, that Cylindropuntia fosbergii is a hybrid with C. bigelovii as one of the parents. However, neither genetic nor morphological studies have yet been able to determine a second parent, and C. fosbergii is currently considered a species in its own right.