The original Christmas tree was a Spruce, which is distinguished by its cone shape and whorled branches. The needles of a Spruce are attached singly to the branches rather than in bunches, in a spiral ...

One of the most interesting evergreens is the weeping blue spruce (Picea pungens 'Pendula'). This cultivar of the native Colorado blue spruce was a selected seedling grown in a tree nursery in the ...

Little is known about the paleoecological histories of the three spruce species (white spruce, Picea glauca; black spruce, P. mariana; and red spruce P. rubens) in eastern North America, largely ...

This is a preview. Log in through your library . Abstract Previously published reports indicated that germination of some tree seeds might be controlled by an endogenous germination periodicity. It is ...