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Parasites⁵³

Although all flowering plant parasites agree in having structures known as haustoria (Fig. 57), which penetrate into the living tissues of the host, they differ quite widely in a number of other respects. Some are complete parasites as they lack chlorophyll and so are unable to utilise light energy to manufacture sugars. Others, which have green leaves, make their own organic nutrients and derive from the host mostly water and inorganic nutrients. Some parasites are attached to roots, others to trunks and branches.