Dendrobium orchid root. Light micrograph of a section through an aerial root from a Dendrobium sp. orchid. The outer tissue (velamen radicum, not show
Image details
Contributor:
Science Photo Library / Alamy Stock PhotoImage ID:
2ACKX0FFile size:
50 MB (3.2 MB Compressed download)Releases:
Model - no | Property - noDo I need a release?Dimensions:
4283 x 4084 px | 36.3 x 34.6 cm | 14.3 x 13.6 inches | 300dpiDate taken:
21 December 2011Photographer:
DR KEITH WHEELER/SCIENCE PHOTO LIBRARYMore information:
Dendrobium orchid root. Light micrograph of a section through an aerial root from a Dendrobium sp. orchid. The outer tissue (velamen radicum, not shown) is composed of hexagonal cells. These are dead cells with lignified walls that contain pores that take up water. The next layer, the exodermis, is a ring of cells with walls of suberin that contain passage cells for water flow. The next layer is the cortex of parenchyma cells (deep blue). The central core has an outer ring (endodermis) with thick walls (grey), then an inner ring (pericycle, blue), and next a ring of vascular bundles with alternate rings of xylem (red) and phloem (blue), surrounded by fibres (red). Magnification: x37 when printed 10 centimetres wide.