Echinocactus is a genus of cacti that is native to regions of central Mexico, but can also be found in the southwest United States (Boke, 1957). It is commonly located in the Sonoran and Mohave regions, where there is less than 130 mm of rain annually(Arizona Sonora Desert Museum, 2015). There are only 6 accepted species: E. grusonii, E. horizonthalonius, E. parryi, E. platyacanthus, E. polycephalus and E. texensis (Arizona Sonora Desert Museum, 2015). E. grusonii, also known as the barrel cactus, is a popular species found in cultivation due to its ease of growth and tolerance to a wide range of factors (IUCN, n.d.). Unfortunately, it is considered rare and endangered in the wild due to habitat fragmentation (IUCN, n.d.).
A common trait found within Echinocactus is the appearance of woolly ovaries found in the apex of the plant, where flowers propagate (Arizona Sonora Desert Museum, 2015). This distinction is what differs this genus from Ferocactus, another genus that is barrel-shaped, that also produce spines and funnel-shaped flowers that range from yellow to magenta in colour. The Echino- portion of their genus name comes from the phylum Echinodermata, which include animals such as starfish, because of the appearance of spikes.
Echinocactus is usually known as an ornamental plant, although many parts of these plants could be used for food. For example, the pulp from the stems of E. platyacanathus is used to produce a traditional Mexican candy known as acitrón or biznaga (known in Mexico as “barrel cactus”) (Jiminez-Sierra and Eguiarte, 2010). Acitrón is also used to produce sweet tamales, chilli sauces, and is used in fruit punch (Jiminez-Sierra and Eguiarte, 2010). The dry, woolly fruits of many of these species are edible and can be eaten by birds in order for seed dispersion to occur. Animals such as the bighorn sheep (Ovis canadensis) or javelina (Tayassuidae) can consume the entire cactus and can disperse seeds to greater distances (Arizona Sonora Desert Museum, 2015). The First Nations people in Mexico use the wool found on the apex to create fabric (Jiminez-Sierra and Eguiarte, 2010).
Arizona Sonora Desert Museum. (2015). Flowering plants of the Sonoran desert. Retrieved at http://www.desertmuseum.org/books/nhsd_echinocactus.html
Boke, N. H. (1957). Comparative histogenesis of the areoles in Homalocephala and Echinocactus. American Journal of Botany 44(4), 368-380.
IUCN. (n.d.). Echinocactus grusonii. Retrieved at http://www.iucnredlist.org/details/40962/0
Jimenez-Sierra, C. L. and Eguiarte, L.E. (2010). Candy barrel cactus: A traditional plant resource in Mexico subject to uncontrolled extraction and browsing. Economic Botany 64(2), 99-108.