Wood Anatomy Lecture VI

Variations in Angiosperm Wood Anatomical Characters of Taxonomic
Use

I.  Variation in vessel size within a growth ring
     A. Ring porous
     B. Semi-ring porous
     C. Diffuse porous

II. Pattern of vessel aggregation
     A. Exclusively solitary
     B. Radial groups of 4
     C. Radial or oblique
     D. Tangential arrangement
     E. Clusters

III. Perforation Plates
     A. Simple
     B. Multiple
     C. Number of scalariform bars

IV.  Pit and wall details of vessel elements
     A. Spiral thickenings
     B. Minute pits
     C. Opposite or scalariform pits
     D. Alternate pits
     E. Vestured pits

V. Vessel element lumen features
     A. Abundant tyloses
     B. Tyloses sclerosed
     C. Deposits or gum

VI. Metric features
     A. Number of vessels in transverse view
     B. Tangential diameter (not applied to ring porous)

VII. Other Dead Axial Cells
     A. Fibers
     B. Fiber-tracheids (Distinctly bordered fibers)
     C. Tracheids
     D. Spiral thickenings
     E. Septate

VIII. Axial Parenchyma Patterns
     A. Absent or rare
     B. Apotracheal
          1. Diffuse
          2. Diffuse-aggregate
          3. Concentric
     C. Paratracheal
          1. Scanty
          2. Vasicentric
          3. Aliform
          4. Aliform confluent
          5. Banded
               1. 1-seriate bands
               2. 2- to 4-seriate bands
               3. > 4-seriate bands
               4. Bands closely spaced (>6/mm)
     D. Marginal/Boundary
     E. Storied

IX. Ray Features seen in tangential view
     A. Long = > 1 mm high
     B. Seriation
          1. Exclusively 1-seriate
          2. 2- or 3-seriate
          3. 4 to 10-seriate
          4. > 10-seriate
     C. Aggregate rays
     D. Rays of two distinct widths
     E. Metric features (can use transverse sections)
          1. < 4/mm
          2. 4-12/mm
          3. >12/mm

X. Ray Features seen in radial view
     A. Homocellular = only procumbant cells
     B. Heterocellular = marginal cells
          1. 1 to 3 marginal cell rows
          2. => 4 marginal cell rows
     C. Bi- or tri-seriate parts narrow