We got the Blues! In the Ordovician period, around 450 million years ago, the first land plants appeared on Earth. Not until about 250 million years later in the Triassic period would the Earth see the appearance of flowering plants,(there were however, prior to this time, in the late Devonian period, free-sporing plants ). It is generally believed that the first flowers were white in color appearance. Today the most common flower color is still white followed by yellows and the oranges, red/pinks/magenta, and least common of all the purples,violets,lavenders and blues. What is responsible for flower as well most leaf colors, is the result of reflected light from various plant pigments. A group of compounds called anthocyanidins are the basic ingredients. They are named for the flowers in which they were first found, such as the scarlet pelargonidin from the geranium or Pelargonium, the purple petunidin from the Petunia, or the blue-violet delphinidin from the Delphinium. -1 There are many factors that may affect a flowers exact color such as temperature, soil pH, or nutrient levels as well as locality to name a few. Age may also play a factor as many flowers will pass through stages of color say from blue to pink as they fade. This may be a subtle signal to pollinators to indicate a flower is past its prime. After all flower color is present not for our pleasure, much as it may seem, but as attractants to moths, butterflies and a multitude of insects and birds who serve as pollinators insuring a species continued existence. Sometimes the color we perceive is not at all what an insect may see such as a red perceived as a white in an infrared spectrum. (conversely, white and yellow may be perceived as light blue). Combine the anthocyanidin compounds with sugar in plants to produce the more common anthocyanin pigments responsible for our fall leaf colors, among other colors. There are other pigments in leaves as well, such as the flavonols (yellow) and, of course, chlorophyll (green). Flavonols, and the colorless (to us) flavonoid pigments, not only affect the color caused by primary pigments (co-pigmentation), but by absorbing ultraviolet light they also are readily seen by insects -2 Major plant pigments and their occurrence -3 Pigment-Common types- Where they are found-Examples of typical colors Chlorophylls Chlorophyll Green plants Green Carotenoids Carotenes and xanthophylls (e.g. astaxanthin) Bacteria. Green plants (masked by chlorophyll), vegetables like carrots, mangoes and so on. Some birds, fish and crustaceans absorb them through their diets Oranges, reds, yellows, pinks Flavonoids Anthocyanins, aurones, chalcones, flavonols and proanthocyanidins Produce many colors in flowers. Common in plants such as berries, eggplant, and citrus fruits. Present in certain teas, wine, and chocolate Yellow, red, blue, purple Betalains Betacyanins and betaxanthins Flowers and fungi Red to violet, also yellow to orange . 1,2,3- with thanks to Dr. Leonard Perry, Extension Professor University of Vermont photos by SE Popp
Posted on: Fri, 11 Jul 2014 00:15:00 +0000
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