Chía and its wild relatives: A superfood Salvia (Lamiaceae)

Abstract

Societal Impact StatementAlternative crops are a promising approach to address the global food shortage that is exacerbated by climate change and wealth disparities. Some of these alternative crops are traditional food plants that have been widely traded for centuries, whereas others have only recently become more popular. Chía is a traditional native “superfood” that is the fruit of three distinct mint species. Chía (Salvia hispanica) is commercially cultivated and shares nutritional properties with California thistle sage (Salvia carduacea) and desert chía (Salvia columbariae). These wild relatives of S. hispanica are adapted to arid conditions and have potentially valuable genetic variation for the development of chía agricultural varieties. The development of nutritious, drought‐tolerant crops such as chía will increase the resilience of people to the impact of climate upheaval.SummaryIn the Spanish language, the word chía refers to the nutlet fruits of several Salvia species native to Mesoamerica. The process of domestication of S. hispanica altered several traits, including the absence of shattering fruits, which makes harvest easier and mechanizable. S. hispanica is commercially cultivated in Mexico, South America, Australia, and less so in Europe and Africa. Other edible chía species are not commercially cultivated, including S. carduacea, and S. columbariae. These Californian chías are traditionally harvested by hand since the fruiting calices shatter and release the nutlets. Here we compare these three edible chía species, review their uses by native peoples, describe their morphology, summarize their natural distributions and cultivation, and provide an identification key. Native peoples in North America have traditionally used chías for food, medicine, and oil. S. hispanica naturally occurs throughout areas of Mexico that receive summer monsoonal rains. As such, it is a summer annual with an erect habit and cauline, simple leaves. In contrast, the Californian chía species are distributed through areas of the Mojave and Sonoran deserts that receive winter rains. They are winter annuals and their rosettes of lobed, pubescent leaves are typical adaptations to arid conditions. Nutlets in these chía species are similar when dry, but cultivated S. hispanica nutlets produce extensive mucilage when wetted, while the other chía produce mucilage to a lesser extent. As consumer interest grows in superfoods like chía, crop breeders may use wild chía to breed varieties appropriate for areas affected by drought or in desert agroecological systems.