A field guide to urban plants: building awareness
I beheld a “weed”
But when its name was revealed
True beauty I saw
(Japanese Haiku, loosely translated)
Blindness to plants
Most people can recall the last wild animal they saw. But is that the case with a plant outside the house? Or perhaps a tree by the side of the road? A hedge? A particular flower? If we notice plants at all, then mostly it is just as a pleasant background or as urban greenery. Very few take a closer look, spending a moment examining the shape of the leaves or the interesting features of the flower. Are there any insects visiting the plant?
At the end of the twentieth century, the American botanists Elisabeth Schussler and James Wandersee coined the phrase ‘plant blindness’, by which they mean ‘the inability to see plants in their own environment’. This is not only regrettable but also dangerous: it implies a failure to appreciate the value of plants and therefore a lack of interest in their protection and conservation. This is especially serious in towns, where we desperately need plants to alleviate the effects of climate change. Indeed, we need plants, both big and small.
Miniature ecosystems develop in the cracks between paving stones
Valuable ecosystems
Our towns and inner cities are dominated by concrete and tarmac, but if you look more closely you will find plants almost everywhere. Right under your very feet! Often it is the rubbish, broken glass, chewing gum and innumerable cigarette ends that capture the eye. Yet in amongst all this you will discover small, stubborn, stoical fragments of green. Between the paving stones, in the cracks of gutters and in the crevices of walls these little anarchists have dug themselves in. A multitude of herbaceous plants, grasses, mosses, ferns and seedlings of trees and shrubs have found a niche, adapting to the extreme conditions. In order to do so, they must defy pressure from pedestrians, traffic, drought, heat, the sun’s radiation, soil compression, salt spreading and other pollution, and not least the street-cleaning vehicles and all too often an obsession with ‘tidiness’. Despite all this, many survive to provide microhabitats for numerous insects and other organisms.
Kerb squatters: beautiful and useful
These interlopers have many uses to us humans: a thick growth in the cracks between the paving stones increases their stability; green crevices absorb surface moisture, help the water to seep away, contribute to cooling and bind in the soil and dust. In addition, wild plants in our towns play a significant role in the urban ecosystem, offering food and protection to other organisms such as wild bees, beetles and ants. Moreover, a second look (if one is needed) will reveal their beauty, not only of their petals but also the shapes of their leaves, and how different species grow together.
Intriguing assemblages of species can arise in urban micro-niches. Here three species of fern coexist in the same crevice in an old wall: rustyback, maidenhair spleenwort and hart's-tongue.
Diversity in town
Towns invariably conjure up an image of concrete, tarmac and glass. But a closer look will reveal an extraordinarily rich variety of plants and animals. Why are towns so diverse? In the perception of most people, towns and wildlife are at opposite ends of the spectrum. Urban areas, after all, are largely made up of artificial structures and building materials, a fact hard to deny. However, towns are also endo- wed with a rich biological diversity – as is shown, for instance, by the over 500 species of wild plants being found in the cracks of German pavements. One reason for this is that the sheer range of structures and land-uses offers innumerable habitats to plants and animals. Verges, flowerbeds, street trees, green spaces, hedges and old walls, green rooves, undeveloped building plots, gardens, cemeteries, parks and more all make vital contributions to urban biodiversity. Even the buildings themselves accommodate many species, such as birds and bats. In fact, towns are nowadays more species-rich than many areas in the countryside because, compared with intensive and industrial modern farms, they offer a wide variety of niches attractive to wildlife. Towns and cities, it turns out, are fast becoming a refuge for wild species sadly no longer welcome in much of the countryside.
For thousands of years, towns have been commercial centres and thus key meeting places for people from far and wide. At these crossroads of humanity, seeds from all over the world are able to establish themselves and spread. Garden plants colonise new locations and, when their novelty has worn off, exotic animals are released by their weary owners – it is especially the heat-loving species that are able to take advantage of the warmer urban climate, also known as the urban heat island effect. This is why towns all over the world have a large proportion of non-native plants and animals, and also the reason we will encounter many so-called neophytes, or non- native species, in this book.
Vegetables and cereals
Even tomato, wheat, millet and sunflower seedlings can often be found on street corners. It may have been that someone threw away their kebab with tomatoes or was feeding seeds to the birds. How good it would be if these seedlings could grow to full size and provide us with fresh food in the town! Of course, they need earth to flourish, whereas the gaps in the urban environment are usually too small and dry and are compacted by being driven over and walked on continuously. It might be feasible, though, to exploit the areas around our urban trees to grow our food – as can be seen in occasional examples guerilla gardening. With climate change, some of our food plants will do better under trees than in bright sunlight. Urban vegetable gardening in raised beds across a network of small public areas throughout our towns also adds to biodiversity. At the same time, we town dwellers can become reacquainted with how foods are produced.
The fundamental message here is that all plants are useful to something and that each species has its own beauty and wonder just waiting to be appreciated.
You have been reading an extract from A Field Guide to Urban Plants: Common Species of Pavements, Walls and Waste Ground by Alexandra-Maria Klein and Julia Krohmer, published by Pelagic Books. You can order a copy by clicking here.
