Sensational journalists sometimes refer to something called the greenhouse effect, by which they mean that every time we use an aerosol, chemical deposits accumulate in the upper atmosphere which will raise the earth's temperature, melt the polar regions and eventually turn Guildford into a seaside resort.
But anyone who has spent any time in a greenhouse will know that there are far more noticeable and important greenhouse effects. One is the mysterious accumulation of wooden boxes which fall to bits if you pick them up. Another is the tendency of small pots to get jammed together and to break when you separate them. The most common, though, is the tendency of the greenhouse floor to get covered in fuzzy stuff which is neither quite dead nor alive.
This particular greenhouse effect is already present in nature, unlike the wooden box and jammed pot syndromes. The whole of the world is covered in greater or lesser degree by a sort of fuzz. If nature began life in a primordial soup, we have now got on to the primordial salad course.
Lawn is the tidiest fuzz there is. It is sometimes said that lawns in gardens are totally unnatural. What nonsense! If anything in gardens is unnatural, it is deck chairs, swings swinging from trees, stone gnomes and of course, greenhouses. Lawn, which is a natural mix of grass, clover, reeds and anti-hills, occurs wild on many a Chiltern hillside, all over Yorkshire, throughout Ireland and alongside most motorways. Indeed, lawn in the wild is often neater than garden lawn.
Lawn is fuzz which has got its act together.
Rather carelessly, mould has got a bad name for itself. Most of the time it grows inoffensively on the parts of nature that other growths can't be bothered to grow on – white on land, green at the seaside – but occasionally it has made the tactical mistake of growing on things in the kitchen which we think are useful: tomatoes, mushrooms, bread and so on. Even then, it was partly our fault as we left the things lying around so long that mould thought we were finished with them.
If you think it is disgusting, remember that it is no more disgusting than snow. If you still think it's disgusting, I would keep clear of woods; zmost trees have mould.
Lichen is lawn which thinks it's moss, or perhaps moss which thinks it's lawn – either way, it's a dried-out version of both and always looks dead. It likes growing (or dying) on rocks, walls, churches, the side of the tree facing Iceland, and posters for holidays in Sweden. It has a range of five different colours: rust-red, rust-brown, rust-orange, rust-green and off-rust.
What marks lichen off from all other moulds is that nobody is quite sure how to pronounce it. Some say 'liken', some rhyme it with 'kitchen'. When you're writing a book about it, luckily, this is not a problem you have to worry about.
Moss is simply lawn trying to grow in wet conditions. I once knew a man who had a garden in such boggy country that when he built a tennis court, he referred to the game played thereon as moss tennis. It was quite fun, if you don't mind the balls not bouncing.
Nature's reproductive system, at most levels, operates the same way that informed opinion tells us the Chinese will fight World War III: send out 500,000, and one should get through. In other words, for every one seed that grows into a mighty tree, half a million seeds bite the dust, except they don't bit the dust – they lie around in a kind of sludge under the tree, unable to believe that they will never germinate. They get eaten, washed away or rotted down.
This is most noticeable in London for a few days every summer, when all the plane seeds in the city blow around dangerously in bicyclists' faces and I, personally, put on a pair of motorbike goggles. The rest of the year I use these goggles for wearing when I am chopping onions – very effective against the tear-producing chemicals of that vegetable.
On one hot summer's day I went to answer the doorbell in the middle of an onion-slicing session and opened the door wearing only shorts and goggles, waving a sharp knife. The Jehovah's Witness outside fled at once.
A slight diversion, perhaps, but you don't often find nature guides telling you how to deal with unwanted missionaries
Any large green object which drapes itself artistically over the seaside rocks, along the high water mark or round your knees when you swim, can be classed as seaweed though I have always thought that sealawn would be a more marketable name.
What makes seaweed very special is that it is the only thing outside the fish and bird kingdoms that actually migrates. When you see seaweed aimlessly drifting around in the sea, it is in its own quiet way setting out on an immense summer cruise to warmer parts, the Mediterranean perhaps, or off to the Saragossa Sea to visit relations and swap gossip. Months later, through some miraculous homing device that we don't quite understand yet, it returns to the very same spot near Skegness or off the Mumbles. No wonder it flops across the rocks. It's knackered.
Its only natural enemies are children, who try to turn it into weather-forecasting devices, and the Welsh, who try to turn it into bread. Both attempts are disastrously unsuccessful.
There are two basic species of seaweed, if you are interested in further study; the kind you can pop in your fingers and the kind you can't.
Lying close to the ground, about 0.5 centimetres underneath, are vast quantities of lawn seeds, waiting only for a mixture of warm weather and wet to germinate. In the right conditions this produces a sort of green four o'clock shadow right across the land, almost visible on satellite photographs.
The nearest equivalent in human terms is the start of the London or New York marathon; thousands of little pathetic organisms struggling for a chance to make glory. Most of them won't last the course. Don't bother with either.
It's odd how the cuckoo gets blamed for so much. Not only for throwing little birds out of nests and for causing letters to The Times, but for spitting. Those blobs of froth on grass are not cuckoospit at all, of course. For one thing, birds cannot spit; for another thing, those blobs are caused by farmers salivating into the undergrowth to signify the striking of a bargain.
In spring, many ponds are surrounded by a kind of jelly with little black dots inside. Throw the first 499,999 away and keep the next. It will develop into one of the glories of nature, the tadpole, which is shaped as excitingly and beautifully as an Exocet or an avocado pear. Unfortunately, it then develops into one of the failures of nature, the frog, which goes on to seek out its natural enemy – the motorcar – and be crushed by it.
Any plant which climbs up another plant, or across a wall, or over an abandoned garden roller, or up your legs if tales about the fertility of rain forests are true, can be classified as ivy until you are more expert.
Ivy is usually classified as a parasite, or at least a hanger-on, which shows how little naturalists follow things through. If an ivy plant completely covers a tree and the tree then dies, the ivy will continue growing in the shape of the tree even when the tree rots and vanishes. The same is true if the ivy gets to the top of the tree and continues without it.
The great dream, the so-far unrealised ambition, of the ivy world is to do the same to a church. What finer coup could there be than to have a church-shaped ivy plant with no church inside it? There is already believed to be a castle in Ireland which is ⅔ ivy.
It is dangerous to eat ivy. The same is true of churches.
Nature Made Ridiculously Simple 1983