Purity of the sacred lotus, or escape from contamination in biological surfaces

Post date: May 2, 2012 6:53:35 PM

[ W. Barthlott, C. Neinhuis, Planta (1997) 202: 1 http://www.springerlink.com/content/4m4jnt03qlvaywjl/fulltext.pdf ]

In the past 25 years, scanning electron microscope studies of biological surfaces have revealed an incredible microstructural diversity of the outer surfaces of plants. Microstructures such as trichomes, cuticular folds, and wax crystalloids serve different purposes and often provide a water-repellent surface, which is not rare in terrestrial plants. Water repellency is mainly caused by

epicuticular wax crystalloids which cover the cuticular surface in a regular microrelief of about 1±5 lm in height (Baker 1982; Jeffree 1986).

Water-repellent, rough surfaces were represented by leaves of the sacred lotus (Nelumbo nucifera Gaertn.), kohlrabi (Brassica oleracea L.), taro [Colocasia esculenta (L.) Schott] and the petals of a composite (Mutisia decurrens Cav.).

Look at these fantastic pictures!

Scanning electron micrographs of the adaxial leaf surface of smooth, wettable (a±d) and rough, water-repellent (e±h) leaf

surfaces. The smooth leaves of Gnetum gnemon (a) and Heliconiadensi¯ora (b) are almost completely lacking microstructures while

those of Fagus sylvatica (c) and Magnolia denudata (d) are characterized by sunken and raised nervature, respectively. The rough

surfaces of Nelumbo nucifera [Lotus] (e) and Colocasia esculenta (f) are characterized by papillose epidermal cells and an additional layer of

epicuticular waxes. Brassica oleracea leaves (g) are densely covered bywax crystalloids without being papillose, and the petal surfaces of

Mutisia decurrens (h) are characterized by cuticular folds. Barsˆ 100 lm (a-d) and 20 lm (c-h)