In other words, the "smiley faces" are just an illusion created by viewing a slice of the leaf's round vascular bundles from above, through a microscope lens. By Bethania Palma.

IN the course of a broad investigation of the comparative anatomy of the monocotyledons at present in progress at the Jodrell Laboratory, Kew, an exceptionally interesting arrangement of vascular ...

Increasing vascular bundle density has long been believed to be a key initial step in C 4 plant evolution. However, the regulatory mechanisms governing leaf vein density have remained elusive.