Opuntia toumeyi, Arizona prickly pear cactus, spines

Rose, Contributions from the U. S. National Herbarium 12: 402, 1909

Holotype; Herbarium; Herbarium; Herbarium; Herbarium (O. toumeyi-like); Herbarium (O. toumeyi-like); Herbarium (O. toumeyi-like)

Original Description

What is Opuntia toumeyi?

Opuntia toumeyi is a low but prickly pear cactus with pads narrowed towards the base. The cactus may appear yellowish-green and has brownish-white or white spines.

Details

There are 1-4 spines but usually 1 or 2. There is often one central spine that is dominant and longer than all the other spines in an areole (sometimes it is missing on some pads but rarely all pads, and sometimes there is more than one). The dominant spine is porrect or semi-reflexed.

Flowers are bright yellow, sometimes with a bit of bronze or orange at the base. Flowers may change to orange or even reddish-orange on day two. The stigmas are green, and the filaments are yellow.

Ploidy is unknown.

Other Notes

Spination may seem similar to that in O. flavispina. However, the spines are not true yellow, and the long spine is not reflexed so intensely. Also, O. toumeyi is lower and more spreading than O. flavispina, and glochids are red-brown or paler but not yellow.

O. toumeyi patches may seem yellowish compared to other Opuntia species. Mature cladodes are often 15-20 cm long. O. toumeyi grows in the gravelly foothills and mountains in southern Arizona and in Sonora, Mexico.

This Opuntia would make an excellent medium-sized garden plant. Its ultimate cold-hardiness is unknown.