Christmas tree pests and weeds Douglas fir, grand fir, white fir and California red fir on Christmas trees in Santa Clara County. Camellias imported from California to British Columbia in 2003 and early 2004 caused a significant SOD scare in the horticultural and Christmas tree industries. The detection of "P. ramorum" led to plant recalls in Canada, and a series of steps meant to quarantine the disease before it spread. The 2003–2004 SOD scare extended to Washington and Oregon nurseries and farms. Douglas-firs are vulnerable to the two plant pathogens that cause Rhabdocline needlecast, "Rhabdocline pseudotsugae", and "Rhabdocline weirii". "R. weirii" affects only Douglas-fir trees.
Noble polyhedron 'dual' covers both kinds. The dual of a noble polyhedron is also noble. Many are also self-dual: Noble polyhedron A noble polyhedron is one which is isohedral (all faces the same) and isogonal (all vertices the same). They were first studied in any depth by Hess and Bruckner in late 19th century, and later by Grünbaum. There are four main classes of noble polyhedra: If we allow some of Grünbaum's stranger constructions as polyhedra, then we have two more infinite series of toroids: We can distinguish between dual structural forms (topologies) on the one hand, and dual geometrical arrangements when