Cortical bundle

• Title

  Cortical bundle

• Definition

  A vascular bundle found in the cortex of a stem.

• Notes

  Lignier (1890) was the first to stress the value of stem and petiole anatomy in the subfamilial classification of Lecythidaceae. The presence of cortical bundles helps to characterize the family, and their arrangement (inversely vs normally oriented) is a useful diagnostic character at the subfamilial level. The cortical bundles are inversely oriented (i. e. xylem outside, phloem inside) in the subfamilies Planchonioideae (now called the Barringtonioideae) and Foetidioideae and normally oriented (i.e. phloem outside, xylem inside) in the Napoleonaeoideae (now considered a separate family, the Napoleonaeaceae) and Lecythidoideae (Lignier, 1890; see Table 2 in Mori, 1974). There are numerous cortical bundles in the Planchonioideae [Barringtonioideae], Foetidioideae, and Lecythidoideae and only 4 in the Napoleonaeoideae [Napoleonaeaceae]. There are at least 36 other families of dicotyledons with cortical bundles (Metcalfe and Chalk, 1957) and, thus, the presence of cortical bundles indicates that a plant being identified may belong to the Lecythidaceae (with cortical bundles} and not to the Mrytaceae {without cortical bundles).

• Related Terms

  Cortex

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