Punic War POWs

On April 1, 2003, David Greenberg posted "The POW in the American Imagination - Why we're obsessed with American soldiers captured by the enemy" on Slate. In the article Greenberg says that the Romans and Carthaginians crucified captured enemy generals during the Punic Wars.
Is this true? Did they really kill enemy commanders? And if so, did they actually use the slow, torturous method of execution known as crucifixion?

Full Article: Punic War POWs.

• Crucifixion
• Mithridates
• Spartacus