The fascination of plants

By Leighton Jones - 18th May 2012

I was at junior school when Man first landed on the moon. But I remember that my grandmother was deeply sceptical about the whole enterprise - convinced, in fact, that our lunar satellite harboured dangerous creatures and that Apollo 11 would bring back little green men.

As it turns out, the intervening forty-odd years have shown that we probably need to worry a great deal more about the little green life-forms on our own planet than those from space. After all, everything we eat comes from plants one way or another, but they constantly face a barrage of threats - man-made and otherwise: emerging pests and diseases, deforestation, global warming, loss of biodioversity.

Plants are incredible 'machines' that soak up simple ingredients - carbon dioxide and water - and combine them with the aid of solar light energy to make the sugars on which we all depend. They give us grain, vegetables, leaves, fruits and seeds for food. They provide culinary variety with herbs, spices, flavourings, thickeners and colourings. Even the meat we eat comes from animals that eat plants (or animals that eat things that eat plants), and fish from a foodweb that comes to rest with tiny photosynthetic organisms.

Apart from food, their vascular system yields fibres like hemp and jute for materials and fabrics. Their wood helps provide us with shelter, paper and fuel for our fires. The lives laid down by their ancestors of millions of years has yielded fossil fuels and the raw materials for plastics.

And, setting aside the utilitarian, plants give us great aesthetic pleasures: the striking colours and perfume of flowers or the smell of freshly mown grass and, when we look closely enough, the intricate, artistic detail of their microstructure.

For scientists, plants provide fundametal challenges. How do they sense gravity, so that roots grow down and stems grow up? Why do they bend towards the light? What tells them when to shed their leaves, when to retreat into scaly buds for the winter or when to flower?

They share intimate relationships with the many living things around them. Many pay insects with nectar for carrying a cargo of pollen to their sexual partners. Fungi wrap their microscopic threads around many a plant root, exchanging nutrients and water from the soil for some of the plant's sugars. Legumes such as peas and beans provide shelter for bacteria that convert atmospheric nitrogen to ammonia, keeping the nitrogen cycle turning and providng the plant with nitrogenous nutrients.

And for bloggers they also provide 'lexiophilic' entertainment. Some of my favourite words come from the world of botany: xylem and phloem, cotyledon, plasmodesmata, Equisetum, gibberellin, thylakoid ......

Plants are fascinating on all levels - and we neglect them at our peril.