Lenticel

The dark horizontal lines on silver birch bark are the lenticels.[1]

A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of gymnosperms and dicotyledonous flowering plants.[2] It functions as a pore, providing a pathway for the direct exchange of gases between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gases. The name lenticel, pronounced with an [s], derives from its lenticular (lens-like) shape.[3] The shape of lenticels is one of the characteristics used for tree identification.[4]

  1. ^ "Lenticel". The American Heritage Science Dictionary, Houghton Mifflin Company, via dictionary.com. Retrieved on 2007-10-11
  2. ^ Gibson, Arthur C. "Bark Features in General Botany". Archived from the original on 2013-11-17. Retrieved 2012-08-19.
  3. ^ Esau, K. (1953), Plant Anatomy, John Wiley & Sons Inc. New York, Chapman & Hall Ltd. London
  4. ^ Michael G. Andreu; Erin M. Givens; Melissa H. Friedman what the. "How to Identify a Tree". University of Florida IFAS extension. Archived from the original on 2013-05-14. Retrieved 2013-03-07.