Nannorrhops ritchiana MSI
From Palmpedia - Palm Grower's Guide
Though not as cold tolerant as the super cold hardy palms, this palm can survive an amazing variety of climates, from dry desert, to tropical humid, to cold Mediterranean. However, it is not as happy in that last climate and extended periods of cold may do this palm in. It does seem to survive brief periods of cold even a bit below 15F however. Some argue this is the most adaptable palm in existence because of its wide climate tolerance- arguably wider than any other palm's.