Most plants get their coloration from pigments, but an endangered South African cycad gets its unique silvery-blue hue from wax crystals and an underlying chlorophyll-rich layer, according to a recent study. Researchers say understanding how such layers work could pave the way for creating materials that protect from UV and water exposure. Cycads, sometimes described as “living fossils,” are an ancient group of cone-producing plants that appeared around 270 million years ago, predating even the dinosaurs. The study examined the “remarkably glaucous” or bluish leaves of Encephalartos horridus, the Eastern Cape blue cycad. The species is native to shrubland and rocky areas of South Africa. It’s listed as endangered due to declining subpopulations and poaching. The study explained that land plants are typically coated with a water-repelling layer called a cuticle, which protects plants from environmental stresses. Cuticular wax comes in two types: intracuticular wax found inside, and epicuticular wax (EW), found outside the cuticle. The genus Encephalartos, which includes cycads, diverged around 9 million years ago and evolved to have substantial layers of EW. “To the best of our knowledge, visually detectable EW deposits have been primarily documented in angiosperms [flowering plants] and are largely absent in other major plant lineages,” the researchers wrote. “Thus, studying the unique properties of an extant gymnosperm species such as E. horridus may provide valuable insights into plant adaptations to challenging environments.” Researchers learned that the cycad’s EW is mostly composed of a wax compound that forms tubular crystals that reflect light from…This article was originally published on Mongabay

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