  We consider the problem of finding a spanning tree with maximum number of
leaves (MaxLeaf). A 2-approximation algorithm is known for this problem, and a
3/2-approximation algorithm when restricted to graphs where every vertex has
degree 3 (cubic graphs). MaxLeaf is known to be APX-hard in general, and
NP-hard for cubic graphs. We show that the problem is also APX-hard for cubic
graphs. The APX-hardness of the related problem Minimum Connected Dominating
Set for cubic graphs follows.
