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On the basis of morphology Chenopodium quinoa of the Andes and C. nuttalliae of Mexico appear to be very closely related species. Artificial hybrids have been secured between the two. It is suggested that both species may have been derived from the same original wild type. A weedy quinoa, C. quinoa var. melanospermum, is known from South America, but as yet a weed race closely related to C. nutalliae has not been reported from Mexico.
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Heiser et al. (1974) studied this question.
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