Remarks on aerophores and the relationship between sterome and stomata in ferns

Zombie leaves: Novel repurposing of senescent fronds in the tree fern Cyathea rojasiana in a tropical montane forest

“…Attempts to clear away senescent leaves of C. rojasiana revealed that they were rooted in the soil (Figure 2B, Appendix S1). Further examination of these leaves revealed that the leaf lamina and parenchyma tissue of the central rachis had rotted away, leaving behind a hollow cylinder consisting of a tough outer sheathing layer of the leaf rachis (the hypodermal sterome; Moran, 2022) enclosing numerous intact vascular bundles (Figure 2C). The decay resistance of these vascular bundles appears to be related to the presence of thick dark‐pigmented layer surrounding the vascular bundles that are apparent in cross sections of living leaf petioles but absent from the close relative C. multiflora Sm., which does not produce “rachis roots” (Figure 2C).…”