Both “silver”and green saw palmettos (Serenoa repens) can be found growing at the Oslo Riverfront Conservation Area. They are the same species. What is going on?
You cannot tell what’s going on with a magnifying glass or hand lens. You need a scanning electron microscope to discover that silver saw palmettos have a greater abundance of epicuticular wax on their leaves.
In a paper titled Florida’s Wax Palm: The Silver Form of Serenoa Repens, researchers “found that in the green form the epicuticular wax formed thin, flat, peeling sheets, while in the silver form the wax formed in thick, irregular patches of fused rod-like extrusions. This striking difference in epicuticular wax accounts for the color difference, but the ecological significance of this feature remains unknown.”
Silver saw palmettos has a limited range: .”The silver form occurs naturally primarily in a narrow, discontinuous belt along Florida’s Atlantic coast, stretching from St. Johns County to Dade County, and occasionally inland, particularly along the central ridge in Highlands and Polk counties.” Remember that the central ridge, long ago, was beachfront real estate
This extra waxy layer may help to protect the plant from desiccation in windy, salty coastal places and may help to reflect sunlight thereby reducing the moisture loss through leaf transpiration.
Enjoy the Oslo Riverfront Conservation Area 