T REES AND W OOD Softwoods are coniferous trees that have a needle-like leaf structure. The most common varieties in North America are pine, spruce, redwood, cedar, and fir. Fir, pine, and spruce are the three types of wood most often used to produce lumber. There are many different vari- eties of pine trees, but they can be separated into two main types, yellow and white. Stage scenery has tradi- tionally been constructed of white pine. White pine is an extremely workable wood for building scenery, as it is soft and easy to cut, it has a straight grain pattern, and it is widely available at a reasonable price. Yellow pine is much heavier and is more susceptible to splitting. Fir is quite often used to make interior trims and moldings. At least a cursory understanding of the mechanics of how trees grow can help you understand how wood will react when it is used for building stage scenery. Because trees grow naturally, they are prone to quirks that cannot be entirely eliminated by the lumber milling process. The cambium is responsible for transporting water and nutrients from the ground to the leaves. It is really a mass of tiny tubes much like blood vessels. These fibers are very strong and pliable along their length, but they are not bound together all that well. It is possible to strip the fibers from some trees into long strings. This works with other plants as well. Hemp fibers are stripped from the stalk of that plant and then twisted into rope. You may think of a stalk of celery as being indicative of the mechanics of the structure of a tree. The stalk will bend along its length, but will easily snap across its width. After it does, the stringy fibers that make up the