Art of Nikolas Ilic: Tree Designs!
These trees (especially third from top, and first) could look natural and like the right kind of tree. Color is good.
Vector Trees Illustration Set
Google Image Result for http://drawn.ca/wordpress/wp-content/uploads/2009/07/navie-peach-beech.jpg
Trees Screen Print by Eloise Renouf More
Jon McNaught illustration tree cutters in a forest. Nice mix of patterns.
Guestbook Tree Illustration by Anne Herbst, via Behance
Tree Watercolor Illustration simplistic design of the trees and arangement also watercolor
The Copperleaf Tree by Evajuliet (Very pretty watercolor painting utilizing masking fluid.)
Woodland limited edition giclee print от EloiseRenouf на Etsy, $25.00