Tulip Poplar. Tulip Poplar is not a true Poplar but rather it is in the Magnolia family. It gets its name from the profile of the leaf which is somewhat shaped like a tulip. It is a great fast growing tree which will make one of the straightest trunks in the plant kingdom. It has one of the best yellow fall colors of any of our natives except maybe for Hickory. It has fascinating greenish yellow flowers with orange markings, but unfortunately they are 80-100' up in the tree. If one wants a fast growing shade tree, this is your answer.