I agree with
Jennifer on this one - except I think there's a tiny neutral vowel after the tree! ka-TREE-a-na, or similar.
When RL Stephenson (or was he Stevenson? Memory fades ...) wrote the novel, a lot of people with no Scottish connections assumed it was ka-tree-OH-na; that got given in good faith to little 19th-century girls, but perhaps we are living in more scholarly times - oh, how I do hope so! People do seem to be checking their sources and origins, including the saner posters on this excellent board, who regularly educate and entertain. Thanks, folks - you know who you are!