Title: Clustered planarity testing for trees 
Speaker: Radoslav Fulek, Columbia University, New York
Date: October 7, 2014

Abstract:

We show that clustered planarity testing can be carried out in
polynomial time for trees with vertices partitioned into three
parts. We also prove the corresponding variant of the strong
Hanani--Tutte theorem that was known to fail if the graph is allowed
to contain a cycle.