Noun
vascular bundle (plural vascular bundles)
(botany) A strand of xylem, phloem, and their associated tissues within a eustele or atactostele.
Nymphaeaceae (water lilies) have reticulate veins, a single cotyledon, adventitious roots and a monocot like vascular bundle. Source: Internet
The increase in vascular bundle thickness further seems to correlate with the width of plant axes, and plant height; it is also closely related to the appearance of leaves and increased stomatal density, both of which would increase the demand for water. Source: Internet