Query: Trees from the Northwestern US that can't be found in Canada
Domain: plants
Relevant documents:
Sequoia sempervirens
Juniperus monosperma
Pinus lambertiana
Willamette Valley ponderosa pine
Knobcone pine
Pinus jeffreyi
Calocedrus
Fraxinus anomala
Notholithocarpus
Carya washingtonensis
Juniperus osteosperma
Chrysolepis
Pinyon pine
Acer grandidentatum
Picea breweriana
Umbellularia
Chamaecyparis lawsoniana
Pinus monophylla