Form

• The leaves on the corkscrew black locust grow in a compound form. This means that one "leaf" is made up of several smaller leaflets. The end of the leaf has a single leaflet, while the other leaflets sit opposite each other along the length of the main stem. Each leaf on the tree holds an average of 13 leaflets. The leaflets overlap, giving the leaf a feathered appearance.
  
  

Size

• The corkscrew black locust leaf measures 8 to 12 inches long and approximately 4 inches wide. Each leaflet is 1 to 2 inches long and 1/2 to 1 inch wide. Young leaves start out short and add length as they mature.
  
  

Color

• The leaflets of the corkscrew black locust are bright green on the upper surface. The underside of the leaflets have a duller and paler green tint. The tree is deciduous and the leaves change to a pale yellow in the autumn before they drop. The color change is not showy.
  
  

Shape

• The corkscrew black locust's overall leaf shape is similar to that of a fern frond. The individual leaflets are rounded with an oval shape. As a member of the pea family, the leaflets resemble those on a garden pea plant or sweet pea. The edges of the leaves are smooth.
  
  

Thorns

• The corkscrew black locust bears thorns at the base of the stem, where the leaf meets the branch. The thorns measure less than 1/2 inch long and usually only grow on the lower shoots to protect these leaves from grazing animals. Although small, the thorns are painful if stepped on. Consider this hazard when choosing a planting site for your corkscrew black locust.