University Of Tasmania
152863-Leaf hydraulic conductance is linked to leaf symmetry in bifacial, amphistomatic leaves of sunflower.pdf (560.77 kB)
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Leaf hydraulic conductance is linked to leaf symmetry in bifacial, amphistomatic leaves of sunflower

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journal contribution
posted on 2023-05-21, 13:00 authored by Richardson, F, Gregory JordanGregory Jordan, Timothy BrodribbTimothy Brodribb
The hydraulic implications of stomatal positioning across leaf surfaces and the impact on internal water flow through amphistomatic leaves are not currently well understood. Amphistomaty potentially provides hydraulic efficiencies if the majority of hydraulic resistance in the leaf exists outside the xylem in the mesophyll. Such a scenario would mean that the same xylem network could equally supply a hypostomatic or amphistomatic leaf. Here we examine leaves of Helianthus annuus to determine whether amphistomaty in this species is associated with higher hydraulic efficiency compared with hypostomatic leaves. We identified asymmetry in the positioning of minor veins which were significantly closer to the abaxial than the adaxial leaf surface, combined with lower Kleaf when transpiration was driven through the adaxial rather than the abaxial surface. We also identified a degree of coordination in stomatal behaviour driven by leaf hydraulics, where the hydraulic conditions experienced by an individual leaf surface affected the stomatal behaviour on the opposite surface. We found no advantage to amphistomaty based on efficiencies in construction costs of the venous system, represented by vein density:stomatal density, only limited hydraulic independence between leaf surfaces. These results suggest that amphistomaty does not substantially increase whole-leaf hydraulic efficiency.


Publication title

Journal of Experimental Botany










School of Natural Sciences


Oxford Univ Press

Place of publication

Great Clarendon St, Oxford, England, Ox2 6Dp

Rights statement

© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License (, which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Repository Status

  • Open

Socio-economic Objectives

Ornamentals, natives, flowers and nursery plants