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Chrysomyxa Weirii
''Chrysomyxa weirii'', is a fungus that causes a disease, commonly known as Weir's cushion rust, of spruce trees. It is mostly a cosmetic problem, causing yellowish spotting and banding on spruce needles, but in some cases can cause severe premature defoliation.“Weir’s Cushion Rust or Spruce Needle Rust”, Cornell University, 2013 http://www.plantpath.cornell.edu/Trees/WeirCshRust.html Weir’s cushion rust can also disfigure and reduce growth of spruce trees by targeting the tender needles of newly emerging Shoot (botany), shoots.Stanosz, Glen, Chrysomyxa weirii on Colorado Blue Spruce in Wisconsin, Plant Disease. 86: 1051.3, September 2002 This pathogen's spores are spread by wind and water splash and germinate to infect newly developing needles on the same spruce, or neighboring spruce trees.Stanosz, Glen R., “Weir’s Cushion Rust of Spruces”, University of Wisconsin-Extension, April 25, 2004 Unlike many other rust disease pathogens, ''C. weirii'' is Heteroec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spruce
A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfamily Piceoideae. Spruces are large trees, from about 20 to 60 m (about 60–200 ft) tall when mature, and have whorled branches and conical form. They can be distinguished from other members of the pine family by their needles (leaves), which are four-sided and attached singly to small persistent peg-like structures (pulvini or sterigmata) on the branches, and by their cones (without any protruding bracts), which hang downwards after they are pollinated. The needles are shed when 4–10 years old, leaving the branches rough with the retained pegs. In other similar genera, the branches are fairly smooth. Spruce are used as food plants by the larvae of some Lepidoptera (moth and butterfly) species, such as the eastern spruce budwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
