Common or Garden: Encounters with Britain's 50 Most Successful Wild Plants

By Ken Thompson

We often imagine that rarity is special - we seek out the most uncommon wild plants to tick off our lists, while overlooking the extraordinary appeal of the species we encounter day-to-day. Yet it's these plants -the most successful, able to adapt and thrive - which are truly fascinating.

Botanist, writer and expert gardener Ken Thompson has set out to chart Britain's fifty most abundant wild plants and reveal the secrets of their success. He explores the roots of their common names, from the dog rose to Yorkshire fog, and explains the key traits that have led them to flourish across Britain. And, along the way, he shares his tricks for making your garden a haven for green life.

Stunningly illustrated by Sarah Abbott, Common or Garden is a celebration of the everyday wonder of the plants that you can see, as Thompson enthuses, 'before you even have lunch'

• Language: English
• Publisher: Profile Books
• Release date: May 25, 2023
• ISBN: 9781800811454

Ken Thompson

Dr Ken Thompson teaches on the Kew Horticulture Diploma, and was for twenty years a lecturer in the Department of Animal and Plant Sciences at the University of Sheffield. He writes regularly on gardening for various publications. He is the author of Where Do Camels Belong? and Darwin's Most Wonderful Plants.

Book preview

Common or Garden

Encounters with Britain’s 50 most successful wild plants

First published in Great Britain in 2023 by

Profile Books

29 Cloth Fair, Barbican, London EC1A 7JQ.

www.profilebooks.com

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Typeset in Minion Pro to a design by Henry Iles.

Copyright © Ken Thompson, 2023

The moral right of the author has been asserted.

All rights reserved. Without limiting the rights under copyright reserved above, no part of this publication may be reproduced, stored or introduced into a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), without the prior written permission of both the copyright owner and the publisher of this book.

A CIP catalogue record for this book is available from the British Library.

ISBN 978-1800811447

eIBSN 978-1800811454

Common or Garden

Encounters with Britain’s 50 most successful wild plants

KEN THOMPSON

Contents

Introduction: Common is rare

1 How not to be common

2 Making the cut

3 Five shrubs

Blackthorn

Dog rose

Elder

Hawthorn

Hazel

4 Green and flat

Annual meadow-grass

Common bent

Creeping bent

Creeping soft-grass

Crested dog’s-tail

Perennial rye-grass

Red fescue

Rough meadow-grass

Smooth meadow-grass

Sweet vernal-grass

Yorkshire fog

5 Flat and not so green

Common mouse-ear

Daisy

Germander speedwell

Greater plantain

Ragwort

Ribwort plantain

Selfheal

White clover

Yarrow

6 Green and not so flat

Cock’s-foot

Common couch

False oat-grass

Tufted hair-grass

7 Mistaken identity

Field woodrush

8 Two buttercups

Creeping buttercup

Meadow buttercup

9 The alien

Sycamore

10 Dangerous relations

Cow parsley

Hogweed

11 Prickly customers

Creeping thistle

Spear thistle

12 In for a splash

Ash

Pedunculate oak

13 The scrambler

Goosegrass

14 The all-rounder

Herb-Robert

15 The weed

Common chickweed

16 The liana

Ivy

17 Another prickly customer

Holly

18 The survivor

Bracken

19 A dandelion for all seasons

Dandelion

20 Jam today

Bramble

21 One and a half docks

Broad-leaved dock

Common sorrel

22 The stinger

Common nettle

A last word: Connections

Information sources

Acknowledgements

Index

INTRODUCTION

Common is rare

In 1965, on his 15th birthday, the naturalist Peter Marren was given a copy of a newly published reference book, The Concise British Flora in Colour by the Reverend William Keble Martin (I too have a copy – almost everyone over 50 with an interest in the British flora does). From that moment Marren’s path was set. He began to tick off Britain’s wild plants in his copy. Several decades on, he realised that there were just 50 plants that he hadn’t managed to see. For a naturalist and author, the next step was obvious: why not try to find all the missing ones – in a single year – and then, of course, write a book about it?

Marren’s eventual title for his book was Chasing the Ghost – referencing his quest’s toughest assignment, the ghost orchid (Epipogium aphyllum), one of three orchids on his missing list. All orchids have extremely tiny seeds, containing more or less no food reserves and the seedlings rely on finding, and then parasitising, a specific fungus. In most orchids this dependence is short-lived, and the plant goes on to make most of its own food. But some orchids continue to steal everything they need from the fungus, a characteristic that defines them as mycoheterotrophs (Greek for ‘fungus-eaters’).

The ghost orchid is one of these. Because it has no need to appear above ground except when it flowers, which it doesn’t very often, the ghost orchid can disappear completely below ground for years, or even decades. Combined with its small size and extreme rarity, this makes it an extremely hard plant to find. In fact, by 2009, no-one had seen it for 23 years, and it was generally believed to have gone for good, in the UK at least. But that year amateur botanist Mark Jannink found it again in a Herefordshire oak wood – a single 5cm-tall white stem, with a single pale flower. So the ghost does still exist – just. Did Peter Marren find it? Read his (very enjoyable) book and find out. But the whole story illustrates the hold rare plants (and rarity generally) have on our imagination. And it’s worth noting that Jannink’s apparent stroke of luck was no such thing. His discovery of one diminutive specimen was the result of detailed research into all previous ghost orchid discoveries – habitat, time of flowering, weather patterns – followed by staking out ten likely sites and visiting them regularly throughout the summer.

Which all makes you ponder the enduring lure of rarity. Peter Marren was prepared to spend a whole year finding his last 50. Mark Jannink spent an entire summer finding just one of them. Marren’s quest provided the enjoyment of visiting some nice bits of countryside and the satisfaction of ‘completing the set’. But rarity itself was the main appeal. It’s not as though the plants themselves were anything special. Most of us would have trodden on the ghost orchid itself without even noticing it. Indeed, after locating his quarries, Marren usually has more to say about the view than the plant he’s come to see. He compares pipewort, Eriocaulon aquaticum, for example, to ‘a six-inch nail sticking out of the water’.

I count myself as some kind of botanist, yet, looking down Marren’s list, I noted that I’d personally encountered just one of them. Well, actually two, but the other one was in Germany, where it is more common, which I think counts as cheating. In fact, if all Marren’s 50 disappeared tomorrow, no-one but a tiny handful of dedicated botanists would notice.

So it’s all about the rarity. And yet, paradoxically, rarity is common. Not just common, but dead common, indeed all but ubiquitous. In the natural world, whether we’re talking about plants or beetles, spiders or fish, nearly everything is rare. To take just one example: trees are big, obvious things, so you would think by now we would have found all the world’s tree species. Not at all; our best guess is that about 9,000 tree species remain to be discovered. Many of these ‘missing’ trees grow in remote, usually tropical, places, but mostly they’re just rare, which is why no-one (so far) has bumped into them.

But you don’t have to go to the tropics to discover how common rarity is. From 1981 to 2001, Jennifer Owen counted and identified all the beetles caught in her Malaise trap (an extremely effective device for catching flying insects) in her suburban garden in Leicester. Of those 395 different species, comprising 14,483 individual beetles, only one was unambiguously common; the rest were somewhere between rare and very rare. Other insects were even worse; almost all the 529 species of parasitoid wasps she caught were either rare or very rare, and four were completely new, undescribed species.

Returning to Marren’s list, it’s pure chance that those particular 50 plants happened to be the ones remaining unticked in his copy of Keble Martin. With no difficulty at all, I could have picked you another 50, equally rare, equally hard to find, equally worthy – or not – of providing the raw material for a quest. With very rare exceptions, we know almost nothing about Marren’s 50, or any other 50 rare plants you care to choose; rarity and ignorance go together. One of Marren’s elusive plants (a rare alpine) grows in Britain only on a single barren Scottish mountain top. We have no idea why it occurs in only one place, and only that one place. Rare plants (or animals) leave little impression on human history; they tend not to feature as food or medicines, as they aren’t often encountered. We are surrounded by a vast ocean of plant and animal rarity, of which we are almost entirely unaware.

Meantime, the natural world of which we are aware, and which provides the living background to our lives, is made up overwhelmingly of a small number of common species, which we either take for granted or, more often, hardly notice at all. Few people attempt to celebrate such species, and yet commonness (unlike rarity) really is a rare and rather exceptional quality. Not only that, we also tend to know quite a lot about common species. If (common) species X proves to be useful, that knowledge is worth acquiring, because there’s plenty of it about, and finding it again is unlikely to be a problem. Ubiquity also means that others may have tried a similar experiment, and likewise come to the conclusion that species X is more or less edible, or a cure for dropsy, or whatever. Common plants provide reliable, repeatable experiences. Commonness also means they’re probably relatively tolerant and adaptable, which may be a useful quality in itself.

In short, rarity is often by far the most, and sometimes the only, interesting thing about rare plants. Common plants, on the other hand, are often intrinsically interesting, and my aim, in the rest of this book, is to demonstrate the truth of that assertion, by taking a closer look at the 50 commonest and most successful plants in Britain

In doing so, I take a deliberately jackdaw-like approach to the concept of ‘interesting’, alighting on whatever sparkly baubles happen to attract my attention. Sometimes (in fact, quite often) it’s the name; apparently weird or pointless names can tell you a lot about a plant. Sometimes it’s what they are (or were) useful for, which may range from lighting the houses of the rural poor to telling the age of a hay meadow, or making a musical instrument, or providing a reliable bounce for a ball. Some common plants provide an insight into the latest developments in plant taxonomy, or trigger scientific controversies, such as the nature of the prehistoric landscape. We’ll discover that Britain’s most reviled and persecuted common plants, such as dandelions, nettles and ragwort, are often the most interesting. And along the way we’ll also find that we really can’t avoid Kevin Costner, Morgan Freeman, Gandalf or the national beverage of Argentina.

But, before all that, a couple of introductory chapters. The first briefly considers the ‘why’ question. Why are these 50 our most successful plants? Where are all those plants (the great majority) that manage to be less than ubiquitous going wrong? This, I think, helps us to understand the kind of plants we’re talking about, and should start to make the top 50 feel a bit more familiar. A second introductory chapter considers the ‘what’ question: how do we know what the top 50 are, and what do we mean when we say ‘common’?

CHAPTER 1

How not to be common

At first sight, it seems commonness (and likewise rarity) might run in families. After all, orchids are rare, while some other plants (buttercups, say) are conspicuously common. Unfortunately, this attractive idea is a bit of a red herring. There are certainly plenty of rare orchids, but the early purple orchid is described by Stace (the standard British flora) as ‘frequent to common throughout the British Isles’ and the common spotted orchid is even more common. Neither is going to make it onto a list of ‘Britain’s 50 most common plants’, but nor are they close to being rare. And, while there are some very common buttercups, two of which will feature on our list, there are some very rare buttercups too. Indeed, one of Marren’s quests was for a buttercup: Ranunculus reptans or creeping spearwort (our semi-aquatic buttercups tend to be called spearworts, while our white-flowered aquatic ones are called crowfoots; that’s common names for you).

Nor are buttercups an isolated example. Many of the species on Marren’s list are in genera with common relatives. And among the ranks of (for example) docks, clovers, violets and speedwells, we find some of Britain’s commonest plants, but also some of the rarest.

Habitat specialists

Most plants are specialists, at least to some extent; that is, they are well adapted to survive in a particular kind of habitat, and those same adaptations mean they don’t do nearly as well in others. So, despite being extremely successful in their chosen habitat, they are limited because that habitat isn’t common enough. Visit a British woodland, for example, and you’re likely to find bluebells. If only Britain were covered with trees, bluebell would stand a good chance of being near the top of our list of common plants. But it’s not, so it isn’t.

Bluebell also nicely illustrates the potentially transient nature of commonness. For several thousand years after the end of the last glaciation, once enough time had elapsed to allow trees to re-colonise, but before humans had got to work clearing the wildwood, Britain was mostly covered with trees. Thus bluebell (along with other woodland plants such as wood anemone, ramsons, dog’s mercury, dog violet, greater stitchwort and red campion) would have been more or less everywhere.

For very many plants, an attachment to the ‘wrong’ habitat puts paid to any chance of ending up on our common list. For example, plants largely confined to chalk grassland, heathland, bogs, any kind of wetland (fen, marsh, swamp, lakes, ponds, canals, rivers and streams), mountains, rocks (quarries, cliffs, screes), shingle or dunes cannot hope to be really common. Unlike woodland, most of these habitats have never been common, so their specialist plants can’t ever have been common either. But, like woodland, some of these habitats have waxed and waned over time. Both wetlands and their characteristic plants would have been far commoner in the past before we began to drain them for agriculture.

Climate limits

If you’re out for a stroll on the chalk grassland of the South Downs, you need to be careful where you sit down to eat your picnic. There is a strong probability of sitting on the well-known picnickers’ nemesis, the stemless thistle (Cirsium acaule). Stemless thistle is every bit as spiny and painful as its taller cousins, but, as its name suggests, it forms a basal rosette of leaves and a flowering stem only 2–3 cm tall.

On chalk and limestone in south-east England, stemless thistle is extremely common, but as you head north and west, it becomes less and less frequent. By the time you reach the edge of its distribution in the limestone valleys of the Peak District in Derbyshire, there are only a handful of isolated populations, all of them on south-facing slopes. Climate is clearly implicated, but how?

In south-east England (and France, where it is also common), stemless thistle flowers from mid-summer to early autumn, and every year produces lots of seeds. But, in Derbyshire, flowering is usually delayed until August and ripe seeds are produced only in those years when August and early September are exceptionally warm and dry. In most years, that doesn’t happen. In a typically damp, cloudy British autumn, not only do no seeds ripen, the seed heads and sometimes the entire flowering stem often become infected with grey mould (Botrytis cinerea) and the whole lot just rots. A striking example of the effect of climate is that sometimes just a few seeds develop, and these are always the ones at the southern (and therefore warmest) edge of the seed head. North and west of the Derbyshire Dales and the Yorkshire Wolds, even growing on a warm, south-facing slope is not enough to guarantee some occasional seed production, and the species simply disappears.

Stemless thistle is a classic chalk grassland plant, and that alone would be sufficient to prevent it from graduating to the most-common list. But, even if it weren’t, its exclusion from north-west England, most of Wales and the whole of Scotland by a need for a warm climate would also be enough (there are thistles that will make it onto the list, though).

If a species is common in south-east England and declines further north and west, as summers become cooler and damper, one always has to suspect a climatic influence on some aspect of reproduction. Take, for example, the