This photo shows a fresh, bright, sword fern (Polystichum munitum) frond backlit by the sun and with the dark, shady bank of Ash Creek for a background.
A frontlit shot would have been boring, and the background would have been illuminated, showing how cluttered it actually is.
I often use a sheet of black Foamcore to get this same effect, but it's nice when Mother Nature cooperates and makes the Foamcore unnecessary.