For what reason does Applegate spend so much time discussing the naming of the species?

Unlike people or more social animals, trees of the same type do not need heterogeneous names. Tree names, therefore, usually just identify the tree’s species, so that the name Red is shared by all red oaks. Red offers an exception that there is a palm tree in Los Angeles that calls itself Karma, but jokes that “you know how Californians can be” (7). Red’s joke clearly shows that they thinks the tree’s choice represents a regional personality that overpowers the tree’s species personality. Many other name rules in the novel make similar statements about identity. For example, opossums are all named after the thing they fear most, underscoring this particular facet of their collective nature.