Scientists have discovered how plants create networks of air channels – the lungs of the leaf – to transport carbon dioxide (CO2) to their cells. Botanists have known since the 19th century that leaves have pores – called stomata – and contain an intricate internal network of air channels. But until now it wasn’t understood how those channels form in the right places in order to provide a steady flow of CO2 to every plant cell. Ground breaking X-ray imaging work was undertaken at the University of Nottingham’s Hounsfield Facility.