Brief Introduction to Wood Characteristics I. Density = Weight per Volume A. Industrial Standard = 12% moisture content B. Dependent on 1. Thickness of cell walls 2. Presense of extraneous material II. Texture (Rough vs Smooth) A. Dependent on size and type of wood elements III. Figure (Even vs Uneven) A. Dependent on alignment and sorting of wood elements 1. Even = no big difference between spring and summer wood 2. Uneven = Big difference IV. Strength is in general proportional to density V. Color is dependent on secondary compounds deposited in cells/cell walls VI. Odor is dependent on secondary compounds deposited in cells/cell walls 1. Presence of bacteria and/or fungi can also give rise to nondiagnostic odors VII. Luster is property of reflecting light A. Dependent on amount of parenchyma present B. Pure cellulose -> most lusterous VIII. Hardness = Response to stress A. Dependent on ratio of wood elements (hard) to parenchyma (soft Division: Magnoliopsida (Anthophyta, Angiosperms) Plants producing seeds enclosed in ovary Two Classes A. Liliopsida (Monocotyledonae) B. Magnoliopsida (Dicotyldonae) Two Major Artificial Groups within Magnoliopsida I. Amentiferae A. Flowers produced in aments (catkins) B. Most members have flowers without petals C. Imperfect flowers 1. Monoecious or Dioecious D. Engler & Prantl hypothesized that the Gnetales with unisexual strobile gave rise to primitive angiosperms II. Floriferae A. Flowers not produced in catkins B. Two subgroups 1. Apetalae = flowers without petals 2. Polypetalae = flowers with petals C. Bessey; Bentham & Hooker hypothesized that the Bennettitales with bisexual strobile gave rise to primitive angiosperm