Tracheid Differentiation in Southern Pines During the Dormant Season


  • L. E. Nix
  • K. Villiers


Southern pine, wood formation, tracheid differentiation, dormant season


The differentiation of last-formed xylem tracheids of loblolly (Pinus taeda) and slash (P. elliottii) pines was followed during the overwinter dormant period in the upper Piedmont of South Carolina. Tissue samples taken from the outer portion of the stem of a poletimber-sized tree of each species in November and March were examined microscopically and tracheid transverse cell-wall thickness was measured. Cell double-wall thickness was compared between the two dormant season samples and with that of the previous year's cells of the same radial file. The comparison of cell-wall thickness indicated that the last-formed latewood cells of the annual ring continued to deposit cell-wall material through March and quite possibly into the following spring.


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