Betula alleghaniensis Betula alleghaniensis Betula alleghaniensis, the yellow birch or golden birch, is a large and important lumber species of birch native to North-eastern North America. Its vernacular names refer to the color of the tree's bark. The name "Betula lutea" was used expansively for this tree but has now been replaced. "Betula alleghaniensis" is the provincial tree of Quebec, where it is commonly called "merisier", a name which in France is used for the wild cherry. It is a medium-sized, typically single stemmed, deciduous tree reaching tall (exceptionally to ) with a trunk typically in diameter. Yellow birch is a relatively
Citrus gummy bark viroid Citrus gummy bark viroid The citrus gummy bark viroid (abbreviated CGBVd) is a sub-species of the hop stunt viroid, and thus is a member of the genus Hostuviroid. As the name suggests, the citrus gummy bark viroid causes problems in the bark of the sweet orange tree. Scrapping the bark exposes localized spots or a line of reddish-brown, gum-impregnated tissue around the scion circumference especially visible near the bud union. The discoloration and gumming may extend above the bud union to the main branches of the sweet orange while in severe infection dark streaks of gum-impregnated tissue may also be