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


Subclass Hamamelidae (Artificial class Amentiferae)

Juglandaceae (Walnut Family)
	7 Genera (2 on Campus)
	60 species

I. Leaves
	A. Deciduous
	B. Alternate
	C. Pinnately compound
	D. Estipulate
	E. More or less aromatic

II. Flowers
	A. Monoecious
	B. Axillary staminate aments
	C. Terminal pistillate solitary/spikes

II. Fruit
	A. Drupaceous Nut with indehiscent or dehiscent  husk

IV. Economic Importance
	A. Lumber
		1. Juglans -> Cabinet wood
		2. Carya -> structural strength
	B.  Edible fruits
	C. Fruit husks & bark -> yellow dyes & tannins

V. Range
	A. N.,C.,S America; West Indies;S. Europe;S.,SE Asia



Generic comparison

I.  Juglans (Walnut)
	Latin Jovis glans = nut of Jupiter
	
	A. Chambered Pith
	B. Fruit husk indehiscent

II. Carya (Hickory)
	Greek for Walnut

	A. Homogeneous Pith
	B. Fruit husk usually dehisces along 4 sutures



Species comparison

Juglans

I. J. nigra (Black Walnut)

	A. 9-23 ovate-lanceolate toothed leaflets
	B. Spherical, glabrous or finely pubescent fruit
	C. Nut corrugations rounded, in groups of 1 or 2
	D. Pale brown/buff pith
	E. Dark brown/black, thin interlaced ridges
	F. Wood:  dark brown, medium luster & texture, uneven figure

II. J. cinerea (Butternut, White Walnut)
	
	A. 11-17 oblong-lanceolate toothed leaflets
	B. Ellipsoid/ovoid pubescent fruit
	C. Nut corrugations sharp, in groups of 2-5
	D. Chocolate pith
	E. Ashy gray, broad interlaced ridges

III. J. regia (English/Persian Walnut)
	[royal]

	A. 7-9 entire leaflets
	B. Nut smooth, in groups 1-3
	C. Silver gray bark
	D. Typically grafted onto J. hindsii stock
	E. Wood:  White, medium luster & texture, uneven figure

IV. J. alanthifolia (Japanese Walnut)

	A. 11-17 toothed leaflets
	B. Up to 20 ovoid Nuts on long raceme covered with sticky hairs



Carya

Section Apocarya (Pecan hickories)
	Bud scales valvate

I. C. illinoinensis (Pecan)
	A. 9-17 serrate/doubly serrate falcate leaflets
	B. Ellipsoidal, husk 4-winged from base to apex
	C. Sweet seed	
	D. Wood:  Reddish brown, low luster, course texture, uneven 	
		figure

II. C. cordiformis (Bitternut hickory)
	[heart-shaped]
	A. Sulfer yellow, scurfy pubescent bud scales
	B. Globose/ellipsoidal, husk 4-winged from middle to apex
	C. Bitter seed

Section  Carya (True hickories)

Wood:  Light brown, low luster, course texture, uneven figure

I. C. ovata (Shagbark hickory)
	[ovate-shaped]

	A. Long thin vertical plates seperating from trunk at ends
	B. 5 leaflets

II. C. laciniosa (Shellbark hickory)
	[shaggy]

	A. Long thin vertical plates seperating from trunk at ends
	B. 7 leaflets