Abstract
An exodermis is a specialized type of hypodermis which often occurs in roots. The hypodermis, like the endodermis, is part of the cortex since it is derived from the ground meristem. The hypodermis and endodermis form the outer and inner boundaries of the cortex, respectively. The hypodermis is a uni- or multiseriate layer of cells which are morphologically distinct from those of the neighbouring cortex. External to the hypodermis lies the epidermis derived from the protoderm. In roots, cells of the hypodermis are frequently modified by the presence of suberized walls; in this case the layer is termed an exodermis according to von Guttenberg (1968). A recent survey of 202 species from 54 families of angiosperms has shown that 91% of the species have a suberized hypodermis and that they invariably also have Casparian bands. Conversely, 9% of the species either have no hypodermis or have a hypodermis with un-suberized walls.
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References
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© 1989 Kluwer Academic Publishers
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Peterson, C.A. (1989). Significance of the exodermis in root function. In: Loughamn, B.C., GaÅ¡parÃková, O., Kolek, J. (eds) Structural and Functional Aspects of Transport in Roots. Developments in Plant and Soil Sciences, vol 36. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-0891-8_6
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DOI: https://doi.org/10.1007/978-94-009-0891-8_6
Publisher Name: Springer, Dordrecht
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