Leuchtenbergia (2003)

By Eric Driskill (February 2003)

Subfamily: Cactoideae
Tribe: Cactaceae
Genus: Leuchtenbergia
Species: principis

This monotypic (having only one species) genus is found in limestone soil throughout the Chihuahuan Desert of northern and central Mexico in Coahuila, San Luis Potosi, Guanajuato, Zacatecas and Hidalgo. Leuchtenbergia principis was listed in Appendix I of the first CITES list (1992), but downlisted to Appendix II in CITES 1996. Common names for Leuchtenbergia principis are agave cactus, cob cactus and prism cactus.

These plants are solitary, occasionally caespitose and low-growing, usually 7 to 14 inches high. Their roots are large and fleshy. Stems are globose to short cylindrical and distinctly tuberculate. Ribs are absent.

Tubercles are 4 to 5 inches long, somewhat leaflike and triangular in cross section, with terminal areoles. Up to 6 inches long, the yellowish flattened spines are flexible, papery and often twisted. The plants’ fragrant, yellow funnelform flowers open during the day and often last for several days.

L. principis are popular in cultivation, for they flower freely throughout late spring and summer, and are quite hardy. This has taken a toll on plants in the wild.

According to Wilhelm Barthlott, the cacti were cultivated in Europe as early as 1846. William Hooker then described leuchtenbergia in 1848, honoring Eugene Beauharnais, duke of Leuchtenberg and stepson of Napoleon Bonaparte.

Leuchtenbergias probably are most closely related to ferocactus, and hybrids between the two genera, called xFerobergia, have been made.

I have enjoyed two L. principis in my collection for several years. The older and bigger of the two has bloomed each year. They do not require any unique attention, in my experience. I use the regular soil mix I use with most of my plants, with the addition of a little lime.

In my opinion, these are odd plants that don’t look much like cacti. Many people that see them also find it hard to believe they are cacti.