ONCE AGRICULTURE HAD BEEN DEVELOPED – largely at the expense of the forest – and became a prelude to the creation of the first cities, it threw up new plant mysteries. Why did trees, hacked down like enemy troops in the business of creating fields, so obstinately grow back? How did a weed metamorphose into an edible vegetable? What made one plant kill you, another make you well? The period between the beginnings of Neolithic farming and the advances of evidence-based science in the eighteenth century was rich in myths and fables which attempted to explain these puzzles. They may not be ‘true’ in our contemporary sense, but are fascinating revelations about how the pre-scientific imagination explained the lives and properties of plants, and fitted them into a view of the cosmos
From the plant’s point of view the baptism of cultivation was a mixed blessing. It meant, usually, a great broadening of the variety of forms in which a species could exist, as humans selected or cross-bred for traits they found desirable. Colours, tastes, hardiness, handsomeness could all be teased out from the rich potentialities of a species’ genome. In the extreme case of the domestic apple some 20,000 distinct varieties are believed to have been developed from one aboriginal species. But these pampered variants are often bought at a cost. The development of copious fruiting may mean the loss of disease resistance. Exuberance of petal may mean absence of scent, and therefore of pollinators, as in many rose varieties. It is rare for a portfolio of vegetal qualities regarded as valuable by humans to coexist with the characteristics a plant needs to survive, unassisted, in the wild. Most of the millions of modern cultivated plants would become extinct within a generation if humans were to vanish from the planet.