I first encountered the Madagascar palm (which is not really a palm) at the Tirso de Molino botanical garden in Torremolinos, Spain. It is a very striking plant (I´m not sure you can call it a tree??) that looks like the cross between a cactus and a palm. As you can see from the image above it has some down right wicked thorns! One website that sells seeds for this pseudo palm is rarepalmseeds.com . They also have a lot of information about palm trees in general.
The images with the flowers are from a park in Benalmadena (the next town over from Torremolinos). This one was about 6 feet tall while the ones in Torremolinos were about 7-8 feet tall.
The picture below reminds me of an upside down octopus that is grasping a clump of seaweed in each tentacle.
You can kind of see why this plant got named a palm although if you look at it up close it really has very little resemblance to a palm.