Solanum ehrenbergii ("papa de monte" or "papa güera") is a species with edible tubers, valuable for the people from central Mexico. The farmers seek the tubers in "nopaleras" and "mezquitales'', but more commonly, they can be found in corn and bean cultivated fields, thus the plants are tolerated and encouraged. The environment in which S. ehrenbergii grows is variable, from harsh, in natural conditions , to bening, in the cultivated fields. The hypothesis is that it must exist a pattern of morphological variation in response to the origin of the populations. The objectives of the study were: a] to analyze the pattern of morphological variation between wild and weed populations of Solanum ehrenbergii and b] to document possible taxonomic differences and evolutive trends under management conditions. The methods included the morphological characterization of botanic material and the numerical analyses of data by cluster and principal components. The results indicated, that populations are grouped according to its origin wild or weed. Probably, the morphological variation of S. ehrenbergii is influenced for an incipient process of domestication in response to practices of tolerance, protection and encouragement carried out by the farmers.
Morphological variation of Cosmos bipinnatus (Asteraceae) and its relation to abiotic variables in central Mexico
