Our series on the native trees of the Chicago area is back this week with an in depth look at locust trees.  Locust trees are found throughout North America and Asia and they are classified under one of two different genera; the genus Gleditsia and the genus Robinia.  There are twelve known species of locust trees under the genus Gleditsia including the popular honey locust, and there are ten known species under the genus Robinia, including the...