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 (whitish pink) of younger spring wood and smaller thick-walled tracheid cells (bright white) of older autumn wood. The large circular lacuna (resin duct, centre) is lined with parenchyma cells (orange-brown). Magnification: x70 when printed 10 centimetres wide.
Model release not required. Property release not available.