Betula nigra catkins long, the male catkins pendulous, the female catkins erect. The fruit is unusual among birches in maturing in late spring; it is composed of numerous tiny winged seeds packed between the catkin bracts. "Betula nigra" is a tree that falls into the family of Betulaceae, which is commonly known as the Birch or Alder Family. This family comprises six genera ("Alnus, Betula, Carpinus, Corylus, Ostrya," and "Ostryopsis)" and includes alders, birches, hornbeams, and hazelnuts. Species within this family, along with "Betula nigra", are shrubs or trees that grow along stream sides or in poorly drained soils throughout the Northern
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