Morphological Features of Tracheid Tips Associated With Compression Wood Formation in Larix Leptolepis Gord.

Abstract

Variation in the morphological features of tracheid tips was observed within and among sterns of larch (Larix leptolepis Gord.) with several different angular displacements from the vertical. The formation of compression wood increased with an increasing angle of stern deviation. Decrease in tracheid length occurred with thc development of compression wood within a growth ring. Compression wood also was accompanied by an increase in the occurrence of abnormal tips. Flattened and Lshaped tips of tracheids increased in number with the development of compression wood and the number of smoothly tapered tips decreased, indicating that the intrusive growth between adjacent cells does not proceed smoothIy in compression wood. It is considered that the spatial readjustment of developing cells is restricted in compression wood, and results from the great increase in the rate of cell division. A negative correlation between tracheid length and morphological abnormalities of tracheid tips was found within growth rings, apparently associated with the severity of compression wood development.