DENDROLOGY WOOD ANATOMY LAB III

I.  The first part of this exercise will acquaint you with fundamental anatomical features of
gymnosperm wood. The numbers in (parentheses) following each feature below refers to the slide number in the box labeled Gymnosperm Wood Demos.  The numbers in [brackets] refer to the specimen numbers in the wood identification collection.  You will find the on-line help in the Gymnosperm Wood component of the MUDES of use during this exercise.

PLEASE RETURN ALL SLIDES TO THEIR APPROPRIATE SLOTS AND BOXES WHEN YOU ARE DONE VIEWING THEM. 

Specific objectives for you to strive to master include:  a)  What section (transverse X, radial
longitudinal R, or tangential longitudinal T) is best to use in assessing a particular character
state?  Hints are provided via abbreviations in the outline below.  b)  What are the features
associated with each character that will permit you to classify the state of that character? 

GENERAL FEATURES

 Spring to summer wood transition in growth rings

 	 Abrupt Spring - Summer wood transition. Hard Pines (2) X [29]
 	Gradual Spring - Summer wood transition. Picea (7) X  [25]

Other general features are best determined by inspection of solid wood samples and         application of common sense.

 	Heartwood colored  Juniperus Wood Block [22]
 	Distinct odor  Juniperus Wood Block [22]
 	Distinct taste  Taxodium Wood Block [24] 			
 	Greasy  Taxodium Wood Block [24]

LONGITUDINAL TRACHEIDS

 	Pits > 1 seriate, opposite Pseudotsuga (14) R [27]
 	Spirals in earlywood Pseudotsuga (14) RT [27]
 	Notched pit borders Sequoia (9) R [23]
 	Pits with tori extensions Tsuga (12) R
       
LONGITUDINAL PARENCHYMA

 	Parenchyma present Chamaecyparis (8) XRT Juniperus [22]
 	Parenchyma abundant Chamaecyparis (8) XRT Juniperus [22]
 	Parenchyma end-walls nodular Taxodium (10) T [24]


RAY TRACHEIDS 

 	Smooth Ray Tracheids Larix (4) R [26]
 	Minute Dentate Ray Tracheids Picea (7) R [25]
 	Average Dentate Ray Tracheids Pinus resinosa (11) R
 	Reticulate Dentate Ray Tracheids Pinus echinata (2) R [29]

RAY PARENCHYMA

Horizontal Walls

 	Thin Taxodium (10) R [24]
 	Unpitted Taxodium (10) R [24]
 	Well pitted Picea (7) R [25]
   
Other features

 	Wall corners thickened Sequoia (9) T [23]
 	End walls nodular  Pseudotsuga (14) R [27]
 	> 30 cells high Sequoia,Taxodium (9,10) T [23,24]
 	Crystals present Abies (15) R

CROSS-FIELD PITS

 	1-3 Pinoid Soft pines (1) R [28]
 	1-6 Pinoid Hard pines (16) R [29]
 	Piceoid Picea (7) R [25]
 	Cupressoid  Chaemaecyparis (8) R [22]
 	Taxodioid Taxodium (10) R [24]

RESIN DUCTS

 	Vertical Pinus (1) XRT [28]
 	Horizontal  Pinus, Pseudotsuga (1,14) XRT [28,27]
 	Thick epithelial cell walls Pseudotsuga (14) XRT [27]
  
Number of epithelial cells / horizontal canal 

 	5-6 Pseudotsuga (14) T [27]
 	7-12 Larix (4) T [26]
 




II.  Keying woods

Use the Gymnosperm Wood Component of the MUDES to identify specimens [22] through
[29] in the wood identification collection.

ULTIMATE OBJECTIVE:  YOU WILL BE ABLE TO IDENTIFY 8 GENERA OF SOFT
(GYMNOSPERM) WOOD EITHER BY SIGHT OR BY  MICROSCOPIC IDENTIFICATION BY THE END OF THIS LABORATORY EXERCISE.

PLEASE RETURN ALL SLIDES TO THEIR APPROPRIATE SLOTS AND BOXES WHEN YOU ARE DONE VIEWING THEM.