Betula populifolia Betula populifolia Betula populifolia (gray or grey birch) is a deciduous tree native to eastern North America. It ranges from southeastern Ontario east to Nova Scotia, and south to Pennsylvania and New Jersey, with disjunct populations in Indiana, Virginia, and North Carolina. It prefers poor, dry upland soils, but is also found in moist mixed woodlands. Living only about 30 years, it is a common pioneer species on abandoned fields and burned areas. Gray birch grows quickly to 20 to 30 feet tall and 15 inch trunk diameter, with an irregular open crown of slender branches. The tree often has
Citrus gummy bark viroid observed in longitudinal sections. 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