%0 Journal Article %T Cracking the omega code: hydraulic architecture of the cycad leaf axis %A Alison Ricciardi %A Brett A Huggett %A P Barry Tomlinson %J Archive of "Annals of Botany". %D 2018 %R 10.1093/aob/mcx181 %X The leaf axis of members of the order Cycadales (¡®cycads¡¯) has long been recognized by its configuration of independent vascular bundles that, in transverse section, resemble the Greek letter omega (hence the ¡®omega pattern¡¯). This provides a useful diagnostic character for the order, especially when applied to paleobotany. The function of this pattern has never been elucidated. Here we provide a three-dimensional analysis and explain the pattern in terms of the hydraulic architecture of the pinnately compound cycad leaf %K Cycas revoluta %K cycad %K omega pattern %K anatomy %K xylem network %K xylem hydraulic architecture %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5838846/