"The Flora of North America seems to stop at the Mexico-USA border. Where are all our experts when you need one?" Which part of the North American flora stops at the Mexican United States? There are many genera that bridge that artificial line. Oaks, pines, maples, magnolias, Mahonia, all occur on both sides and in some cases the same species and there are plenty of others that don't range widely in the northern United States but occur throughout the southeast and southwest U.S. If I have the correct greatest diversity of Pinus and Quercus species in the world is found in Mexico. Another interesting twist, the cycad genus, *Ceratozamia *represented by several species in Mexico, Guatemala, and Belize is represent in fossil form from Alaska. Seems to me there is a fairly amount of moving around. Alani Davis