This is the sole species in the genus Leuchtenbergia, making it monotypic. It occurs throughout much of the semi-desert in northern and central Mexico. Despite occurring over a rather large area, plants are sparsely scattered and can be difficult to find. Usually they occur singly, often growing in the shade of clumps of Agave, Hechtia or other shrubs.
Leuchtenbergia principis is an interesting looking cactus with long slender triangular tubercles that have long thin wafery spines at the tips. It is really unique looking and is easily recognisable even when young. It has bright yellow flowers when mature.
The plants need deep pots to accommodate the strong napiform structure formed by the stem base and the rootstock, and a loose mineral soil with a well-drained substrate is recommended. They need a good amount of light, but avoid strong sunlight in midsummer. It does grow better with generous waterings and will grow a lot faster with less tubercle dieback, which looks unsightly. Too much water will cause it to rot but a lack of water will make the tip of the tubercles yellow. Light frost protection is required for safe cultivation. Propagation is usually by seeds, and it grows easily from seed in cultivation.
It is interesting that even though Leuchtenbergia is a monotypic genus it will hybridise with plants in the Ferocactus group to which it is closely related. The resulting plants are called × Ferobergia, and they have stockier tubercles which are darker green and dark hooked spines. The plants do not seem to grow as tall.
Fig. 1 (top) When mature it does form a large turnip-like napiform root so is best grown in a deeper pot
This is a very old plant from one of the first crosses by Piltz.
Text and photos by Tina Wardhaugh.
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