ABSTRACT
Variation in modern maize relates to both recent and ancient cultural events, and in turn these events have been channelled by the biological and physical environment. The highest peak in Huanuco, marking its western boundary, is Yerupaja, the second highest in all the Tropics. Much of the terrain for 100 km to the northeast of Yerupaja lies between 4000 and 4400 m, cut deeply by numerous narrow valleys leading into the Maranon and Huallaga Rivers. Linkages between the natural environment and crops can be quickly clarified by using shifts in vegetation. There are too few meteorological stations to establish patterns of rainfall and temperature in local detail, but vegetation is a clear indicator of ecological potential for cultigens. In order to explain the great variation found within cuitigens, especially in Andean food staples, one needs to understand the history and uniqueness of cultures.
