Plant breathing pore. Light micrograph of a transverse section through a young woody stem from a lime tree (Tilia europaeus), showing a young breathing pore (lenticel) at centre left. The outside tissue of the stem is made of cork (dark-brown) which is composed of dead cells. The cork prevents the ingress of pathogens, loss of water and insulates the stem against fire damage. To allow gas into the stem for respiration, a lenticel is formed in the cork layer. This will eventually form a powdery cork tissue that allows gases into the stem. Magnification: x100 when printed at 10 centimetres wide.
Model release not required. Property release not required.