Lime tree stem, light micrograph 照片檔

Lime tree stem. Light micrograph of a section through the stem of a lime tree (Tilia sp.). At centre is the pith, surrounded by a layer of wood (xylem). A thin cambium separates this from the phloem. An outer layer of collenchyma is enclosed by the outer bark. Magnification: x30 when printed at 10 centimetres wide.