Map of Vegetation Regions/Biomes of North America

[Diana Horton]

Can anyone suggest where I might find a relatively simple (the big picture
- major zones, not every nuance), preferably black and white map of North
American Biomes/Vegetation Regions?  The kind of thing I want is in the 2nd
Edition of Biogeography, except it is a world map.

Thanks!

Diana Horton
University of Iowa Herbarium
Department of Biological Sciences
312 CB
University of Iowa
Iowa City, IA  52242-1297