DR KEITH WHEELER / SCIENCE PHOTO LIBRARY DR KEITH WHEELER / SCIENCE PHOTO LIBRARY
Pine stem. Light micrograph of a section through a single annual growth ring in the stem of a pine (Pinus sp.) tree, showing large thin-walled tracheid cells (light pink) of younger spring wood and smaller thick-walled tracheid cells (dark pink) of older autumn wood. The large circular lacuna (resin duct, centre) is lined with parenchyma cells (blue and brown). The tracheid walls of many cells have bordered pits (green) which pass water and minerals side-ways between cells. Magnification: x70 when printed 10 centimetres wide.
Model release not required. Property release not available.