Native honey locust will typically have huge thorn clusters al over the place including the trunk. As the trees get older, the bark will develop vertical fissures and larger plates of bark will start to lift from the tree. There was a post here not too long ago where someone cut down a large honey locust that showed the typical barl really well. If you can find any leaves they are typical bi-pinnatley compound with very small leaflets maybe 1/4"-1/3" wide by 3/4" to 1" long and oval. You typically will not see many leaves on the ground in winter since they are so small and decompose quickly; you may see some of the leaf stems though.
The wood itself has very distingct sapwood and heartwood; the sapwood is a cream to light yelow and the heartwood is typically a light salmon/orangy tan color. It's a ring porous wood as well.
Black locust has much smaller thorns and typically on the branches more than the trunk. The bark does not lift up in plates but does fissure vertically. Black Locust leaves are Pinnately compound usually and the leaflets are larger, typically 3/4" wide by 1 1/2" long or so. The sapwood I've see is a little whiter than honey locust and the heartwood more brown than honey locust, many times with a greenish tinge.
Hope this helps.
