1, leaf shape: acacia and cajanus cajan have similar leaf shapes. Their leaves are alternate, usually oval or ovoid. Although there are tufted hairs under the leaves of Acacia, the leaves of cajanus cajan have no obvious hairs, but the overall shape is very similar.

2, growth habits: acacia and cajanus cajan can grow into upright trees or shrubs. Their branchlets are slender and have obvious longitudinal edges. This upright growth habit and slender shoots make them very similar in appearance.