Sabal minor - The Dwarf Palmetto, comes from the Southeastern United States, and is reputed to withstand -20C, making it one of the world's most hardy palms.
It is one of the few plams to have costapalmate leaves, which is almost halfway between a fan palm and a feather palm. The leaves are roughly round like a fan, but have a central midrib like feather palms. It grows to about 2.4m (8 feet) and grows most of its trunk underground. It likes boggy ground and can take full sun.
The fact that it is that hardy should make it an ideal palm for UK growers, sailing through any cold snap we can throw at it, but it does have one major drawback, it needs summer heat, and I mean HEAT!
Although hardy to -20C it does not really start into growth until 28 or 30C, which would mean Zero growth over much of the UK, and maybe 10 to 20 days growth in the Southeast.
Howie, The Dwaft Palmetto, pictured right, is my second oldest palm. Grown from seed in 1976.