Machine translation, except where credited.

The ancient order Cycadales (“cycads”), have a pattern of vascular bundles in the leaf axis, seen in transverse section as an inverted “omega”. In the genus Cycas, Tomlinson et al. recreate this system as a 3-dimensional pattern based on images of sequential sections. Each leaflet is supplied by a single trace, from adaxial bundles, renewed […]


The ancient order Cycadales (“cycads”), have a pattern of vascular bundles in the leaf axis, seen in transverse section as an inverted “omega”. In the genus Cycas, Tomlinson et al. recreate this system as a 3-dimensional pattern based on images of sequential sections.

Petiole base displaying the inverted omega pattern.

Petiole base displaying the inverted omega pattern.

Each leaflet is supplied by a single trace, from adaxial bundles, renewed by migration of abaxial bundles, which do not interconnect. Distal leaflets are not at a hydraulic disadvantage because they have a direct hydraulic supply. This approach provides a method for comparison with other extant genera, all of which show leaflets supplied by multiple vascular bundles.

Start typing and press Enter to search

Discover more from Botany One

Subscribe now to keep reading and get access to the full archive.

Continue reading