Columbia subject headings:
Agriculture--North America--Origin.
Indians of North America--Agriculture.
Indians of North America--Ethnobotany.
Harvard subject headings:
Agriculture--North America--Origin.
Indians of North America--Agriculture.
Indians of North America--Ethnobotany.
Princeton subject headings:
Agriculture--North America--Origin.
Indians of North America--Agriculture.
Indians of North America--Ethnobotany.