''Leuchtenbergia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Gree ...

which has only one

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, ''Leuchtenbergia principis'' (agave cactus or prism cactus). It is native to north-central

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

( San Luis Potosi, Chihuahua). The genus is named after Maximilian Eugen Joseph (1817–1852), Duke of

Leuchtenberg Leuchtenberg is a municipality in the district of Neustadt an der Waldnaab in Bavaria, Germany, essentially a suburb of nearby Weiden in der Oberpfalz, and a larger historical region in the Holy Roman Empire governed by the Landgraves of Leuchte ...

and amateur botanist. It is very slow-growing but can eventually grow up to 70 cm high, with a cylindrical stem which becomes bare and corky at the base with age. It has long, slender, grayish-green

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

s 6–12 cm long, with purplish-red blotches at their tips. The tubercles are topped with papery spines, making the plant resemble an

agave ''Agave'' (; ; ) is a genus of monocots native to the hot and arid regions of the Americas and the Caribbean, although some ''Agave'' species are also native to tropical areas of North America, such as Mexico. The genus is primarily known for ...

; old, basal tubercles dry up and fall off. After four years or so, yellow, funnel-shaped flowers 5–6 cm diameter may be borne at the tubercle tips. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is smooth and green, 3 cm long and 2 cm broad. It has a large, tuberous taproot.

Taxonomy

It is related to the genus ''

Ferocactus ''Ferocactus'' is a genus of large barrel-shaped cacti, mostly with large spines and small flowers. There are about 30 species included in the genus. They are found in the southwestern United States and northwestern Mexico. Description The y ...

'', and hybrids have been created between these two genera. File:Leuchtenbergia principis 5.JPG, ''Leuchtenbergia principis'' File:Leuchtenbergia principis 4.JPG, ''Leuchtenbergia principis'' seen from above File:Leuchtenbergia principis 10.JPG, The flower File:Leuchtenbergia principis 106.jpg, The fruit File:Leuchtenbergia principis 122.jpg, Seeds

References

*Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan. {{Taxonbar, from=Q8179748 Flora of Chihuahua (state) Cactoideae Monotypic Cactaceae genera