DENDROLOGY WOOD ANATOMY LAB III - Conifer Wood Features & Identification

I. The first part of this exercise will acquaint you with fundamental anatomical features of

gymnosperm wood. You may wish to review these features on your own - feel free to do so. The

numbers in (parentheses) following each feature below refers to the slide number in the green box labeled Gymnosperm Wood Demos. The numbers in [brackets] refer to the specimen numbers in the brown wooden XRT wood identification slide collection. You will find the on-line help in the Gymnosperm Wood component of the MUDES of benefit during this exercise.

PLEASE RETURN ALL SLIDES TO THEIR APPROPRIATE SLOTS 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?

The NUMBERS in the following outline refer to feature numbers in the softwood datasheet.

NA implies that you will not encounter this feature in your study of our selection of North

American woods.

GENERAL FEATURES

Spring to summer wood transition in growth rings

1. Growth rings indistinct (NA).

3. Latewood conspicuous eg. hard pines (DEMO 2) X [29]

Other general features are best determined by inspection of solid wood samples and

application of common sense.

2. Heartwood colored Juniperus Wood Block [22]

4. Distinct odor Juniperus Wood Block [22]

5. Distinct taste Taxodium Wood Block [24]

6. Greasy Taxodium Wood Block [24]

7. Dimpled grain (NA)

LONGITUDINAL TRACHEIDS

8. Pits alternate (NA)

9. Pits > 1 seriate, opposite Pseudotsuga (DEMO 14) R [27]

10. Tori scalloped (NA) although we will show you an example of strap like extensions

of tori in feature 51 Tsuga (DEMO 12) R.

11. Spirals in earlywood Pseudotsuga (DEMO 14) RT [27]

12. Callitroid thickenings (NA)

LONGITUDINAL PARENCHYMA

13. Parenchyma present Chamaecyparis (DEMO 8) XRT Juniperus [22]

14. Parenchyma abundant Chamaecyparis (DEMO 8) XRT Juniperus [22]

15. Parenchyma end-walls nodular Taxodium (DEMO 10) T [24]

RAY TRACHEIDS

16. Ray tracheids present (Larix, smooth not dentate) (DEMO 4) R [26]

Dentate Ray Tracheids

17. Minute Picea (DEMO 7) R [25]

18. Average Pinus resinosa (DEMO 11) R

19. Reticulate Pinus echinata (DEMO 2) R [29]

RAY PARENCHYMA

Horizontal Walls

20. Thin Taxodium (DEMO 10) R [24]

21. Unpitted Taxodium (DEMO 10) R [24]

22. Well pitted Picea (DEMO 7) R [25]

Other features

23. Indentures Taxodium (DEMO 10) R [24]

24. Wall corners thickened Sequoia (DEMO 9) T [23]

25. End walls nodular Pseudotsuga (DEMO 14) R [27]

26. > 30 cells high Sequoia,Taxodium (DEMO 9,10) T [23,24]

27. Crystals present Abies (DEMO 15) R

CROSS-FIELD PITS

28. 1-3 Pinoid Soft pines (DEMO 1) R [28]

32. 1-6 Pinoid Hard pines (DEMO 16) R [29]

29. Piceoid Picea (DEMO 7) R [25]

30. Cupressoid Chaemaecyparis (DEMO 8) R [22]

31. Taxodioid Taxodium (DEMO 10) R [24]

RESIN DUCTS

33. Normal vertical Pinus (DEMO 1) XRT [28]

34. Traumatic (NA)

35. Horizontal Pinus, Pseudotsuga (DEMO 1,14) XRT [28,27]

36. Thick epithelial cell walls Pseudotsuga (DEMO 14) XRT [27]

RESIN DUCTS

Number of epithelial cells / horizontal canal T

37. 5-6 Pseudotsuga (DEMO 14) T [27]

38. 7-12 Larix (DEMO 4) T [26]

GEOGRAPHIC REGIONS

39-44,46-49 (NA)

45. North America

Time, resources, and scope of objectives limit this class to consideration of woods

endemic to the continent of North America. That's not to say that there are not

plenty of woods worthy of your attention outside the scope of this class, we simply

do not have the time or money to investigate them.

PIT DETAIL

50. Notched pit borders Sequoia (DEMO 9) R [23]

51. Tori extensions Tsuga (DEMO 12) R

II. Keying woods

1. 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 BY EITHER SIGHT OR MICROSCOPIC IDENTIFICATION BY

THE END OF THIS LABORATORY EXERCISE.