Leuchtenbergia principis
"Agave Cactus"

     Leuchtenbergia is a monotypic (single species) genus from northern Mexico. Leuchtenbergia principis is one of the most unique cacti there is. Many cacti have their areoles at the tips of tubercules rather than arranged along ribs. L. principis takes this to an extreme. Its tubercules are long, three sided and topped with harmless papery spines. It's reported it can grow up to thirty inches tall! No wonder it has the common name "Agave Cactus". I think if I encountered one that big in the wild I would assume it was some sort of Agave myself. It grows in grassy areas and with its papery spines it is nearly invisable in habitat. Leuchtenbergia, believe it or not, is closely related to Ferocactus (common barrel cacti). In fact a hybrid exists commonly called a Ferobergia. Intermittently from spring to fall, Leuchtenbergia produce three to four inch round pink or yellow flowers at the tips of the tubercules. These are followed by smooth greenish blue fruits.
     L. principis is not too tricky to grow. It should be grown in light shade in a climate such as mine. It's natural for older tubercules to wither and die. The plant drops the older ones in winter. Use a very quick draining cacti mix and water moderately. It requires a deep pot as it has a substantial tap root. Leuchtenbergia can be propagated from seeds, occasional offsets and even cuttings of tubercules. Though I've yet to have any success with that. Below is a nice sized old one at the Tucson Botanical Gardens.
     Update April 2007. I was at a TCSS sale where Miles Anderson had a spot and picked up this marvelous monstrose form. Each tubercule produces a new plant at the tip. This should be an interesting plant down the road. And then later that same summer, mine flowered.

A nice one
at TBG

The monstrose


in spring

A closer

All images and text are copyright 2005-2009 D.S. Franges, unless otherwise noted.