Natural and Experimentally Induced Dispersion of Aggregate Rays in Shoots of Quercus ithaburensis Decne. and Q. calliprinos Webb

There are two types of sites where aggregate rays in Quercusithaburensis Decne. and Q. calliprinos Webb do not occur naturallyin the tree: branch junctions and small ridges of wood. Partialgirdling of Quercus trunks resulted in the dispersion of aggregaterays which diffused into numerous simple rays. The breakup ofaggregate rays following partial girdling is not a typical woundresponse since wounding is known to stimulate ray enlargement.The disaggregation of the huge rays reflects changes in therelationship between axial and radial signal flows. Aggregate rays, Quercus ithaburensis Decne., Quercus calliprinos Webb, ray differentiation, wood formation, xylem anatomy