A locust tree can be identified by its bark, leaves, flowers and seeds, which varies depending on the type of locust. It can also be identified by its habit, which can be a pyramidal, spreading, round or vaselike shape. The area where the tree grows can also help in its identification. Locust trees are native to the eastern part of the United States.
A locust is a member of the Robinia or Gleditsia genus. The honey locust, Gleditsia triacanthos, is a tree whose leaves appear late in the season. The leaves are pinnately or bi-pinnately compound, with paired leaflets. Both types can appear on the same tree. The leaflets turn brilliant yellow before they fall. The branches and trunk of the honey locust also bear long thorns.
The flowers are cream colored and come in panicles, and they're followed by clusters of long, curved seed pods that can be up to 18 inches long.
The honey locust can grow up to 100 feet high and can be germinated from seeds.
The black locust, Robina pseudoacacia, also has alternate, pinnately compound leaves with smooth, paired leaflets, and its white, fragrant flowers grow in pendants. The fruits are also seed pods. It's somewhat smaller than the honey locust and grows to about 80 feet high.