Septum or wooden bridge in hollow trunks of plants, which are located at the location of the nodes (nodes = thickened areas). The nodes divide the annual wood of the vine into sections, the places between the nodes are called internodes. This septum controls the flow of certain substances (liquids) or allows them to flow in only one direction. The semi-permeable (semi-permeable) partitions in an osmosis are also called diaphragms. See also under morphology and grapevine.
taken from Bauer/Regner/Schildberger, Viticulture, ISBN: 978-3-70402284-4, Cadmos Verlag GmbH