Cortex (botany)

Cross-section of a flax plant stem:
1. Pith
2. Protoxylem
3. Xylem I
4. Phloem I
5. Sclerenchyma (bast fibre)
6. Cortex
7. Epidermis

In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles.^[1] The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation.^[2] The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells.^[3]

^ Allaby, Michael (2019). Allaby, Michael (ed.). A Dictionary of Plant Sciences. Oxford University Press. doi:10.1093/acref/9780198833338.001.0001. ISBN 978-0-19-883333-8.
^ Hine, Robert (18 April 2019). Hine, Robert (ed.). A Dictionary of Biology. Oxford University Press. doi:10.1093/acref/9780198821489.001.0001. ISBN 978-0-19-882148-9.
^ Leroux, Olivier (November 2012). "Collenchyma: a versatile mechanical tissue with dynamic cell walls". Annals of Botany. 110 (6): 1083–1098. doi:10.1093/aob/mcs186. ISSN 1095-8290. PMC 3478049. PMID 22933416.

[allaby-1] Allaby, Michael (2019). Allaby, Michael (ed.). A Dictionary of Plant Sciences. Oxford University Press. doi:10.1093/acref/9780198833338.001.0001. ISBN 978-0-19-883333-8.

[hine-2] Hine, Robert (18 April 2019). Hine, Robert (ed.). A Dictionary of Biology. Oxford University Press. doi:10.1093/acref/9780198821489.001.0001. ISBN 978-0-19-882148-9.

[3] Leroux, Olivier (November 2012). "Collenchyma: a versatile mechanical tissue with dynamic cell walls". Annals of Botany. 110 (6): 1083–1098. doi:10.1093/aob/mcs186. ISSN 1095-8290. PMC 3478049. PMID 22933416.

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