Betula papyrifera resistant to the borer but when grown in subideal conditions the defense mechanisms of the tree may not function properly. Chemical controls exist. It is the provincial tree of Saskatchewan and the state tree of New Hampshire. People sometimes vandalize the bark of this tree by carving into it with a knife or by peeling off layers of the bark. Both forms of vandalism can cause unsightly scars on the tree. Betula papyrifera Betula papyrifera (paper birch, also known as white birch and canoe birch) is a short-lived species of birch native to northern North America. Paper birch is named
Crataegus Crataegus Crataegus (), commonly called hawthorn, quickthorn, thornapple, May-tree, whitethorn, or hawberry, is a large genus of shrubs and trees in the family Rosaceae, native to temperate regions of the Northern Hemisphere in Europe, Asia and North America. The name "hawthorn" was originally applied to the species native to northern Europe, especially the common hawthorn "C. monogyna", and the unmodified name is often so used in Britain and Ireland. The name is now also applied to the entire genus and to the related Asian genus "Rhaphiolepis". The Latin name "Crataegus" is from the Greek "kratos" "strength" and "akis" "sharp", referring