Plants are green because they are not absorbing green light; instead they reflect it. Chlorophyll absorbs most of its energy for photosynthesis in the red & blue spectra. Humans see well using green light because our antecedents evolved in environments abundant in green light (i.e. forests). We share this with most other land animals I expect. There are also pigments in certain plants that can absorb other light spectra to indirectly produce energy for photosynthesis. The dark pigments in plants are there because a) the genetic parents of the plant needed to evolve protection from strong light or b) there is a lack of green pigment due to a nutrient shortage (low N). All (or most) plants have dark pigments that only become visible if there is a nutrient deficiency. Its also probably worth mentioning that the majority of our aquatic plants did not evolve under water but in marshy conditions. Crypts might be one of the few species with adaptations for annual flooding. Some Crypt species probably have the beautiful pink colors on the leaf undersides because they grew in conditions of lower light & wouldn't waste energy by having chloroplasts on the bottom of the leaves. Steve P ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/