- The common domesticated potato originated in South America.
- There are also wild potatoes native to North America, some of which have been used as foods.
- Cimatli is the Nahuatl name for two species of wild potatoes that have been used as food since the Aztecs.
- The two species known as cimatli, Solanum cardiophyllum and S. ehrenbergii, are very closely related.
- These species typically have better disease resistance than the common potato.
- Cimatli tubers are very similar to the common potato, although much smaller and they mature early,
- Cimatli plants are smaller and more delicate than common potato plants.
Cimatli is a Nahuatl (Aztec) word for the tubers of two species of wild potatoes: Solanum cardiophyllum and S. ehrenbergii. They are also sometimes known as papita guera. These tubers have been used by the native peoples of Mexico probably long before the Aztecs, but they are not generally regarded to have been improved from the wild state, unlike the potatoes of South America. They are still collected from the wild and sold at markets in Mexico and occasionally farmed on a small scale. This is not a crop that is likely to have much commercial appeal, but it is well suited to home growing and subsistence cultivation.
The taxonomic history of these two species is a bit complicated. S. ehrenbergii was once classified as a subspecies of S. cardiophyllum, but more recent work has found that it is better supported as a species. The morphological differences between the two are minor and the plants and tubers are basically indistinguishable with the exception of flower color. S. cardiophyllum usually has flowers that are white and light yellow, while S. ehrenbergii has flowers that are white and blue. From the standpoint of someone looking to cultivate and breed cimatli, there is really no reason to pay much attention to the species.
As with the potatoes of South America, we know relatively little about the history of cimatli prior to the arrival of Europeans in the New World. It is a common weed in Mexico and has been continuously used as a wild food. It was apparently eaten by the Aztecs and the Chichimeca. The native peoples of Chihuahua collect tubers from the wild and eat them boiled (Pennington 1969). There have been modern attempts to cultivate and domesticate this species in Mexico, seemingly without much success. Johns (1990), citing Galindo (a text that I can’t access), reported that late blight and brown spot (Alternaria alternata) made it impossible to cultivate cimatli at larger scales. This is somewhat surprising, because S. cardiophyllum and S. ehrenbergii are both reported to have some resistance to late blight.