Mutualism seems particularly important in the tropics. There are no nectarivorous or frugivorous bats north of 32-33 degrees. There are no orchid bees north of 24 degrees. Numbers of plant species with extrafloral nectaries decline rapidly north of 24 degrees. Ants A really interesting case of mutualism is that of the relationship between ants of the genus Pseudomyrmex and plants of the genus Acacia .
Figs have a very unusual flowering system.
The flowers are on the inside of a structure called a syconium , which will develop into the ripe fruit we know as a fig. There is a mutualistic relationship between termites, wood roaches, and some other insects and the protozoa in their digestive system. The termite has evolved a special structure for the mutualistic microorganisms to live in, as has the cow.