ABSTRACT
Plants are the primary source of energy in the biosphere and are therefore the basis of all life on land (19), in fresh water and in the oceans (20). They also sustain life by providing food, shelter and oxygen and play a fundamental role in regulating world climate. For humankind plants provide a great deal more: timber and medicines, fibres and dyes, spices and beverages, oils and fuels. They sustain us spiritually, too, by clothing the landscape and beautifying our parks and gardens (21), as well as the wild places (4, 10, 16).
