Swiftthistle piggybacks on
Briarthorn and
mageroyal, meaning you'll get one every once in a while when gathering those two. For Horde, I'd say Stonetalon might be the best place to go. The Barrens and Ashenvale should be good as well. Briarthorn is usually next to a tree.
Edited, Fri Aug 5 22:11:20 2005 by Kourg