What is the name of the plant whose large flowers look like poms poms (compacted) when in full bloom?

Question

Not mums or moms. But each flower is huge and puffy when in full bloom and crowded together. The plant itself is huge. Some plants have purple flowers and some plants have pink flowers, etc.

Answer 1

I believe your thinking of "Moms"

Answer 2

Could it be Dahlia?

http://images.search.yahoo.com/search/im...

Answer 3

Could be Hydrangeas - see the picture below.