I'm very pleased with this photograph. Accurately capturing the blue-green colour on the upper surface of the leaves was the challenge, and I think I was successful.
Rhododendron campanulatum is a showstopper of a rhododendron, grown in cultivation primarily for its foliage. The blue-green colour on the upper surface of the new leaves is due in part to a thin layer of hairs. Brush off the hairs with your finger, and you discover a typical glossy green upper leaf surface underneath. The bottom of the leaves are a tactile treat - there, the velvety hairs grow so thick that rubbing your fingers along them is like touching a beaver felt hat. This isn't your everyday sort of sensation. As the leaves age, the hairs on the upper surface are lost, while the velvety hairs below turn colour from the white seen here to fawn then finally to cinnamon. The velvety hairs are collectively known as the indumentum.
Speaking of colours, check out Beautifully Blue. This is from a botany weblog which I discovered today: Art and the Bryophyte, run by Julie Ryder and Dr. Christine Cargill in association with the Australian National Botanic Gardens.