Bougainvillea, Bougainvillea spectabilis
Bougainvilleas are big plants.  Give them plenty of room for growth.  The large, unforgiving thorns make pruning a difficult task.  When trained properly, they do well and can bring a lot of color into the landscape.  It's a good idea to plant semi-thornless varieties in planters.
Purple bougainvilleas are probably the hardiest.  The purple goes nicely with the silver in the Buttonwood.  Again, they require regular pruning to keep them under control.
Here is a couple well placed Bougainvilleas.  They make a nice, large barrier to the street here.
They can add a splash of color to a pool enclosure.
Your local nursery should carry several different colors of bougainvillea.
Click on images to enlarge
Alex Driscoll
Certified Arborist #1249A
Plant Guide / Flowering Shrubs / Bougainvillea