This is a very interesting and important subject. Back in 1998, when researching urban agriculture in Belem, located in the Brazilian Amazon Region, I found that such species as Eryngium foetidum, Talinum triangulare and Spilanthes oleracea were gardened in front and backyards and consumed by local populations (See CITIES, 2000, vol. 17(1): 73- 77)
Regarding cassava, which Laura Pereira mentioned in her contribution, the leaf is toxic, (called maniva in Brazil) so locals cook it for a long time and eat it in delicious dishes such as tacaca, maniçoba and Tucupi duck. You can read more, only in Portuguese, in my book "A Cidade da Mangueiras: Agricultura Urbana em Belém do Pará”, edited by FCT and Gulbenkian Foundation, in Lisbon. For those who do not read Portuguese, please login the EMBRAPA site or the Boletim do Museo Paraense Emílio Goeldi (Belem, Brazil), where you might find translations into English of other papers published on this issues.
As to the Andean region, I found the Carla Mejia links very eluminating. FAO has indeed a remarkable work in this field. As I found in my recent research that focuses mostly medicinal herbs, large number of roots, barks, leafs are still in use. So the idea that indigenous peoples forgot about their indigenous foods is totally misleading. They do continue to prepare them as in the old days, but not so often. Species like quinoa and all sorts of potatoes, yacón (used to control diabetes), as maca roots(tonic and good for the bones, a remarkable antiosteoporosis root) and Amaranthus (called Kiwicha in Peru), also Pasammisia pauciflora (Shingi-Panga) are in use and are considered very adequate for children, as they favour their health. Some are simply added to soups as is the case with the last three. I would very much like other input about this region also.
In Costa Rica as in many Central American regions the Sechium edule (Chayote), also consumed in Brazil under the name of xuxu, is a highly valued Cucurbitaceae that they appreciate enormously. As I found days ago, in my home country, Portugal, people have learned with Brazilian immigrants how to cook it also in soups, we eat xuxu more and more, because the current crisis gives families no other choice but to look for nutritious alternatives, meaning dishes that can give more energy to children going daily to school, or to old people that cannot afford to eat meat and fish, as they used to
Isabel Maria Madaleno
PhD in Geography
Portuguese Tropical Research Institute
Lisbon. Portugal
Isabel Maria Madaleno