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        albinism, 
        schizochromism 
         & Variegation 
        
        
        Variegation: A variegated plant has sectors, patches or stripes 
        with two or more different colours, even distinct shades of green. 
        Plants with variegated stems or leaves are often 
        attractive and 
        highly prized. 
        In most species the
        
        stems or leaves are normally green, and variegated epidermis is an 
        uncommon
        
        mutation, termed a
        
        chimera.  A chimeral variegation is due to losing the ability to 
        produce
        
        chlorophyll in some of the plant’s
        
        tissue, so that this tissue is no longer green. Tissues lacking
        
        chlorophyll are usually white or pale yellow coloured (due to
        
        carotenoid
        
        pigments) or red (due to
        
        betalain or
        
        anthocyanin pigments) contrasting with the normal green tissue. 
        There are several forms of variegation, depending on the tissues that 
        have been affected. The variegation in some forms is unstable. The 
        extent and nature of the variegation can vary, and sometimes the plant 
        will return to the green form. In others it is stable and does not 
        change under normal conditions. Because the variegation is due to the 
        presence of two kinds of plant tissue, propagating the plant must be by 
        a
        
        vegetative method of
        
        propagation that preserves both types of tissue in relation to each 
        other.  
        
        
        Albinism: Every once in a while a plant exhibits
        
        
        albinism (completely lacking chlorophyll pigment). This 
        means that its tissue is unable to carry out  photosynthesis. 
         The result is a completely cream-white yellow or reddish plant. This 
        plant will be weaker than a green plant, and albinism is generally a 
        fatal trait (it can't produce its own food and it's not getting it from 
        anything else). Without chlorophyll, the albino plant has no way to 
        manufacture the food needed for survival and growth to maturity. This 
        implies that these plants cannot survive on their own roots and 
        necessitate being grafted on a normal green plant that provides food. 
        Some of these albino plants are indeed very popular, and sought after by 
        collectors.  
        
        
        Schizochromism: The yellow or red appearance of some plants is 
        more precisely caused by another aberration called "schizochromism". 
        Here, though, the specific green pigment (chlorophyll) is missing: every 
        other pigment is present at normal levels. The dominant green 
        colouration is lost, but the plant will still more than likely have 
        normal other pigments that give the yellow overall appearance of stems 
        and the red colouration of spines. 
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