There’s a green sauce in your tacos. Fresh, acid, fruity. This sauce is traditionally made from a little American fruit, the miltomate. Or tomatillo, your taste. And guess what? This is a post all about this strange crop.
Even the species scientific name is sweet: Physalis philadelphica. This is a member of the economically star botanical family, the Solanaceae. But the species has a somewhat less successful story than its cousins like tomato, potato, tobacco or even eggplant. Well, not really less successful, but clearly a species not as illustrious as its more famous co-taxa. Even the Cape gooseberry tends to come to mind first when speaking of Physalis. So let’s do justice to this amazing vegfruit…
Okay, so in miltomate or tomatillo, there’s an appeal to tomato of course. All these names originate as tomatl, a word from Nahuatl, denoting plants bearing juicy and full of seeds fruits (1). E.g., Xitomatl is the classical tomato, that is a red (xi) fruit (with juice and seeds). Miltomatl stands for a ‘tomato’ from the milpa, which is a polycultural agrosystem with maize and beans as main crops. And this sweet name immediately put the species in its agro-ecological origin context: it’s all about a weed turned into a veggie.
This is indeed a noteworthy praxis of any traditional agrosystem: an intrinsic tendency to take benefit from any available resource, turning fields into heavily complex gardens. Many weeds thus become greens when their leaves are edible, or side partners are tolerated for their fruits. This latter situation is indeed the case for miltomates, as the plant is full of alkaloids just like any good member of the Solanaceae. Anyhow many of these ‘forgotten’ edible plants today referred to as neglected crops may well make their come-back someday (1).
This species is thus growing spontaneously in fields. And it has a very interesting status, in terms of domestication. There’s generally a gradation in the interaction between plants and men, once a mutualism is susceptible to develop (that is, when it can serve as food or as any other use by man), from simple gathering in the wild, to tolerance (say, a tree producing fruits right in the middle of the field) to enhancement and even protection (2). Of course, not every interaction may produce domestication of a wild species into a plant with human selected characteristics, but if a plant happens to like or adapt to human managed environments such as fields or gardens, there’s a chance an intimate evolutionary relationship may start. Physalis philadelphica happened to find cultivated lands an agreable place to grow, and Mesoamericans enjoyed their fruits. This was definitely a good beginning. Ethnobotanical studies describe the species as semi-managed, and there is a tendency not only to let it grow but also to try increasing the density of plants within milpas. This was not only via sowing and protecting against pests, but it was going as far as actively fertilizing the flowers, something rather unusual for crop-cohabiting plants (2) (even domesticated are most often left free to open pollination). And this is amazing, because the species is self-incompatible and cannot self. Active human directed pollination might thus well serve a legitimate goal of increasing fruit set and therefore yields. Directed evolution then takes place in spite of coexisting wild forms. Of course, in miltomate, it resulted in bigger fruits, a usual domestication trend.
Now that tacos are taking off, so does this neglected friend. and of course, there is still a lot to say about it… Soon, eventually… :)
(1)- A. Casas, M. Vasquez, J.L. Viveros, and J. Caballero (1996). Plant Management Among the Nahua and the Mixtec in the Balsas River Basin, Mexico: An Ethnobotanical Approach to the Study of Plant Domestication. Human Ecology, 24(4): 455-478.
(2)- B. Pico & F. Nuez (2000). Minor crops of Mesoamerica in early sources (I). Leafy vegetables. Genetic Resources and Crop Evolution 47: 527–540.