Vascular bundles in plants provide mechanical strength, serving as rod-like reinforcements.


"Figure 5: Part of a stem of a robust grass, in cross section. Here mechanical strength of the stem is provided by the vascular bundles set in a matrix of thinner-walled cells, rather like rod reinforcements. Each vascular bundle has an outer sheath of fibres, forming a strong tube in which the two wide vessels can conduct water, and the strand of thin-walled, narrow cells (phloem) can transport sugar solutions with little risk of damage. Just to the inner side of the outer ring of smaller vessels the several layers of narrow cells eventually become thick-walled and provide additional strength in the form of a cylinder to the whole stem." (Cutler 2005:101)

Book section
Design in plantsWIT PressCutler, DF


Vascular PlantsTracheophytaPhylum