Gardeners usually think of hostas as foliage plants, but the flowers of Hosta sieboldiana 'Elegans' (above x 1.76) are as showy as the gigantic "puckered, blue-gray leaves" that have grown by the back door of Chelsea-by-the-Sea into a dramatic clump 4½ feet wide.
Water, unable to wet the cuticle beads up and runs off, carrying dust and soluble contamination with it. This property of self-cleaning ultrahydrophobicity is known as the lotus effect.
A little Photoshopping — zoom tool plus paint-daubs filter — locates our plant's inner Georgia O'Keefe.
And what is a plant cuticle? According to Wikipedia:
Plant cuticles are a protective waxy covering produced only by the epidermal cells of leaves, young shoots and all other aerial plant organs without periderm. [AKA bark]…
The cuticle is composed of an insoluble cuticular membrane impregnated by and covered with soluble waxes …
[It] is one of a series of innovations, together with stomata, xylem and phloem and intercellular spaces in stem and later leaf mesophyll tissue, that plants evolved more than 450 million years ago during the transition between life in water and life on land. Together, these features enabled plant shoots exploring aerial environments to conserve water by internalizing the gas exchange surfaces, enclosing them in a waterproof membrane and providing a variable-aperture control mechanism, the stomatal guard cells, which regulate the rates of transpiration and CO² exchange.
In addition to its function as a permeability barrier for water and other molecules, the micro- and nano-structures of the cuticle confer specialized surface properties that prevent contamination of plant tissues with external water, dirt and microorganisms. Many plants, such as the leaves of the sacred lotus (Nelumbo nucifera) [and our own Hosta Sieboldiana 'elegans'] exhibit ultra-hydrophobic and self-cleaning properties … The lotus effect has potential uses in biomimetic technical materials.
Biomimetic technical materials? Think Velcro.