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01Introduction

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01Introduction

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Chapter 1

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Introduction

It can be hard to explain the lure of the mountains. It is not only rock climbers who are drawn to the peaks, cliffs and ridges of the world’s mountain ranges, gardeners and botanists go there too, in search of alpine plants. There is a feeling of exhilaration as you ascend a mountain range to look for alpines, and the excitement increases the higher you go. The twisting roads, sheer cliffs and glistening snow on the distant peaks all contribute to the sense of anticipation. Around every hairpin bend you stare out of the car window, straining your eyes to spot a splash of colour on the rocky slopes, but it is only when you start walking that these jewels of the hills really reveal themselves. There are plants all around us, but those that shelter in cracks and crevices, cling to rocky ledges or carpet the lofty meadows with colour have a special appeal. Maybe it’s the fact that they live in such hostile conditions, and yet manage to burst into life as spring reaches their high altitude home, that makes them so mesmerising. Maybe it’s the abundance or size of the flowers produced by such compact plants that makes them so appealing. Whatever the reason, some people go to great lengths to grow alpine plants. Most remarkably, many alpines need little special treatment to survive and even thrive in our gardens, an environment very different to their mountain home. You might even have some in your own garden without realising their origins. The aubrieta hanging down a stone wall, the houseleeks clinging to a roof or the crocus pushing through the lawn are all plants of the mountains. How they got there and where they came from is what this book is about.

If you are drawn to the mountains and the plants that live there, you are not alone. Over the centuries, some of the most famous names in botanical exploration, including Sir Joseph Hooker, Robert Fortune, David Douglas, George Forrest and Frank Kingdon-Ward, have made for the hills when exploring new regions. They were often among the first Europeans to study the flora of a continent or mountain range, and it is hard to imagine how they must have felt when confronted with plants that were completely new to them. The first explorers were often members of scientific expeditions sent out to investigate newly acquired territories or recently discovered continents, but they were soon followed by commercial plant hunters, paid by nurseries in Europe to send back plants and seeds for the horticultural industry. New plant introductions often caused much excitement when they flowered for the first time in cultivation. The golden rayed lily (Lilium auratum) in the 1860s, the Himalayan blue poppy (Meconopsis baileyi) in the 1920s and more recently the Chinese Helleborus thibetanus are just some of the species praised in the horticultural press and admired at flower shows across Europe and America. A few alpine plants were already well-known in gardens in the eighteenth century, but during the nineteenth century, as more were collected and their cultivation requirements became better understood, they became more widely grown. This interest continued to grow in the twentieth century, and in 1929, the Alpine Garden Society (AGS) of England and Wales was formed with the aim of

opposite The Chychkan Valley, below the Ala-Bel Pass, northern Kyrgyzstan. Photo: Kit Strange.

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‘promoting an interest in all aspects of alpine plants [and] their cultivation in rock gardens’. How alpines arrived from the world’s mountains is a fascinating story, involving many tales of exploration, adventure and perseverance. It is easy to forget where a plant lives in the wild when it seems so happy in a garden setting, but the plant hunters who sought them out and brought them to our gardens may have undertaken incredibly long journeys, often in little-known, sometimes hostile countries. Just as important to the success of these new plant introductions were the nurserymen and gardeners who cherished and nurtured the treasures sent back from the hills, learning how to grow them to perfection and passing on their skills. Then there are the botanists who identified, named and classified these plants, and continue to do so as the complex relationships between species are gradually becoming better understood. Long before colour photography, many of the new discoveries were painted by botanical artists to illustrate floras and journals, creating an invaluable record of new plant introductions over the centuries. In the late eighteenth and early nineteenth centuries, several botanical journals appeared that illustrated the new plant introductions arriving in Britain from around the world. They included the Botanical Cabinet, the Botanical Register and the longest-running of them all, the Botanical Magazine. The Botanical Magazine is the oldest botanical periodical still being published and is thought to be the world’s longest surviving magazine in colour. Founded by William Curtis (1746–1799), the first part of the Botanical Magazine came out on 1 February 1787 and it has continued in an unbroken series ever since. It was an instant success, with a reported 3000 copies sold of the early issues. After Curtis’s death, the magazine was renamed Curtis’s Botanical Magazine and its fortunes have varied throughout its long life. Early on, it survived competition from similar publications, but in the nineteenth century, rising costs and dwindling subscriber numbers were constant threats. Nevertheless, publication continued into the twentieth century, largely due to the faith and determination shown by two of its editors, Sir William Jackson Hooker, who was editor from 1826 to 1865, and his son, Sir Joseph Dalton Hooker, editor from 1865 to 1904. Both also became Directors of the Royal Botanic Gardens, Kew. Today, over 220 years since it was founded, Curtis’s Botanical Magazine is still publishing the work of the finest contemporary botanical artists. Botanical paintings can be important when it comes to naming and classifying plants. They often accompany the descriptions of new species and so provide a valuable record of the appearance of a plant. For example, Curtis described the silver-edged primula (Primula marginata)

2 Alpines from Mountain to Garden

in his Botanical Magazine in 1792. This species was introduced from the Alps in 1777 and Curtis grew it in his garden. The painting shows the flower colour, leaf characteristics and habit of the plant, including the roots, and so adds useful information that may not be shown in a pressed herbarium specimen. Throughout this book, paintings from Curtis’s Botanical Magazine have been reproduced to illustrate the history of alpine plant introductions from the world’s mountains. The species have been chosen to show the broad range of plants that come under the general term ‘alpine’. However, ‘alpine’ has a number of definitions. Primula marginata, Curtis’s Botanical Magazine, plate 191 (1792). Artist: Francis Sansom.


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What is an alpine? Strictly speaking, alpine plants are found only above the tree line in mountainous regions. The tree line occurs at the altitude at which it is no longer possible for a plant to both produce enough energy to create woody tissue in the form of a trunk and carry out the essential processes of respiration and renewal of foliage. Various factors will influence the ability of a plant to form and maintain a woody trunk, such as duration of snow cover, light levels, day length in the growing season and the effect of repeated damage caused by ice, snow and wind, but the greatest influence is temperature. Temperature decreases with altitude and the tree line is said to occur at the point at which the average temperature of the warmest month is 10°C. Latitude has an effect on day length and temperature, and the altitude at which the tree line occurs comes closer to sea level towards the north and south poles. Above the tree line is the alpine zone, where ‘true’ alpines are found. Habitats in the alpine zone vary enormously. Rocky slopes and cliffs may not have much soil, and the alpines that grow there usually have long taproots that delve deep down to search for moisture and nutrients. Valleys eroded by glaciers

will often have only very thin soils with plenty of exposed rock and debris left by the retreating ice. Erosion of mountain peaks and ridges, particularly by repeated freezing and thawing of water in cracks in the rock, creates steep piles of rubble called scree slopes. Plants that grow on scree slopes have to cope with loose, shifting rocks and stones. Rain will quickly drain through a scree slope, so long searching roots are needed to find water, which sometimes occurs as underground streams running beneath the scree. As a scree slope becomes stable, it can be colonised by more plants and can eventually become a meadow, where soil can collect and the rocks are stabilised by the roots of plants. The scree plants that previously occupied the slope cannot compete with this relatively abundant vegetation and die out, being replaced by grasses and herbaceous perennials that form a rich and diverse tapestry of species. All the plants that grow in these habitats above the tree line can rightly be called alpines. However, many of these habitats also occur below the tree line, in the subalpine zone, and the plants that grow in them are like alpines in every respect except their elevation on the mountain slope. This is where the common definition of alpine becomes unclear. A

above The mountains of North Norway, where the tree line is only just above sea level.

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above A rocky, glaciated valley in the Himalaya of Himachal Pradesh, India. Photo: Joanne Everson.

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steep-sided gorge or a scree slope below the tree line will support a range of plants that are just like the true alpines higher up the mountain, and they are equally suitable for growing in a rock garden or an alpine house. Although a tree is unlikely to be called an alpine, there are many plants that grow in subalpine woods and along streams that are perfect for an alpine plant collection. This means that, in horticultural terms, an alpine is classed as any hardy plant that is a suitable size for growing on a rock garden, alpine trough garden or raised bed. This vague definition covers an assortment of plants, including bulbs, cushion plants, meadow flowers, small shrubs and woodland perennials. Rock gardens themselves provide a variety of different habitats, from free-draining, stony scree beds to shady gullies with more moisture-retentive soil. To simulate meltwater rushing down a mountainside, waterfalls, ponds and streams are often built into rock gardens, and moisture-loving species and aquatic plants can be grown here. The size of a rock garden will also influence the plants chosen. Some of the largest rock gardens are planted with small trees and shrubs and, if appropriate, species are chosen that can give a ‘feel’ of the mountains.

Alpines from Mountain to Garden

In the March 1937 issue of the Quarterly Bulletin of the Alpine Garden Society, Fred Stoker contributed 11 pages of discussion about the meaning of ‘alpine’. He describes how an ‘argument raged’ about the subject at an Alpine Garden Society Annual Dinner and goes on to discuss the various environmental conditions that alpine plants are adapted to. He writes that the term alpine “refers to a manner of life and to the taking of a form necessary to live that life” but does not come up with a simple definition. Prof. John Richards took a light-hearted look at the meaning of ‘alpine’ in the Bulletin of March 2000, writing that members of the AGS know what they want to grow and what is and what isn’t an alpine plant “but there isn’t a word for it”. To complicate matters further, the conditions required to grow alpines also suit some plants from the Mediterranean region. Plants growing near sea level around the Mediterranean may not be frost hardy but a short distance inland, in the nearby hills and mountains, are habitats that support an intriguing range of species that can be grown outside, in free-draining soil and a sunny position. Alpine plants generally need a well-drained soil so that excess water drains away in winter, when they are


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normally dormant. Mediterranean plants need the same soil-type because they are adapted to long, dry summers. They do most of their growing in the mild, wet winters. They may not be called ‘alpine’ but many are undoubtedly suitable for the rock garden. Alpines have adapted to their harsh natural environment in various ways. Forming a low cushion or spreading mat is one of the most common ways to resist high winds and desiccation. Annuals are rare in the alpine zone as there is not enough time to germinate, grow, flower and set seed in the short growing season, but biennials are more common, taking two years to complete their life cycle. Most alpines are low growing, with compressed or prostrate stems, which allows them to survive being buried by deep snow without damage. During the long winter, a layer of snow will give some protection from extremely low temperatures, acting like a blanket. Under the snow, with all water frozen, the alpine will also be kept dry and dormant until the spring, when the thaw will provide plenty of water. All this presents a challenge to the gardener at or near sea level. A relatively mild, damp winter can readily cause alpine plants to rot. They do not become completely dormant, they are

not kept dry and the poor winter light levels lead to etiolation, when the plant tries to grow towards the light and the stem becomes weak and straggly. Growing alpines successfully requires a combination of high light levels, good air movement, cool summer temperatures and welldrained soil or some protection from winter rain.

above Scree slopes form at the base of eroded ridges, here along the Langma La, in the Everest region of the Himalaya. Photo: Joanne Everson.

Plant hunting today One thing that strikes you when reading accounts of plant hunting in the past is the length of time expeditions took. David Douglas set off for western North America in 1824 and returned to London in 1827. Ernest Wilson left for China on a trip for the nursery of Veitch and Sons in 1899 and didn’t return until 1902. The sea voyage to their destination could take months, and once there, plant hunters had to travel without maps, with little or no knowledge of the local people and customs, and often with only just enough money for basic essentials. Nurseries that sponsored or employed plant hunters were very competitive and great efforts were made to be the first to introduce a new species. Not only did these plant hunters have to

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above A stream lined with Primula sikkimensis, flows through a moist subalpine woodland near the Kharta Tsangpo, Everest region. Photo: Joanne Everson.

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survive in distant, unknown regions of the world but they were under pressure to produce results that justified the nursery’s expense in sending them out there. Things are very different today, and successful collecting expeditions last only a few weeks. Today, it is unacceptable to remove plants from the wild without the permission of the landowner or country; collecting is usually closely monitored by the regional authorities and must be carried out in accordance with local and international law. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulates and monitors the trade in threatened plants and animals. The aim of CITES is to protect wild populations by encouraging artificial propagation for trade and monitoring wild

6 Alpines from Mountain to Garden

collection of threatened species to ensure it is carried out in a sustainable manner. The species covered are listed in three appendices to the CITES legislation. Trade is prohibited for wild species listed in Appendix I, but trade in artificially propagated specimens is allowed subject to the granting of a permit. These are species threatened with extinction and their populations are affected by trade. Species listed in Appendix II are not threatened with extinction but they could be if trade is not regulated. Trade in wild and artificially propagated specimens of the species listed on Appendix II is allowed subject to permit, and quotas are often set to regulate this trade. Trade in species listed in Appendix III is monitored, and they may move to Appendix II if thought necessary to protect wild populations. Plants listed on the CITES appendices that may be of interest to alpine gardeners include all orchids (in Appendix I) and all species of Galanthus and Cyclamen (in Appendix II). The Convention on Biological Diversity (CBD) was established in 1992 and is an international treaty aimed at sustaining the rich diversity of life on Earth. It establishes three main goals: the conservation of biological diversity, the sustainable use of its components, and the fair and equitable sharing of benefits from the use of genetic resources. It also reaffirms that countries have sovereign rights over their own biological resources. Countries have drafted national legislation that will affect the way their biological resources can be acquired, used and supplied to others, so plant collectors have to abide by the law of the country in which they are collecting. Permission to collect may be granted with certain conditions, such as the sharing of any profits made from trading in a species, or restrictions may be imposed on the use of the material, such as allowing only scientific research and not commercial use. Botanic gardens and other scientific institutions are often allowed to collect seeds in a country on condition that the seed and any plants raised from that seed are not passed on to a third party. To someone trying to get hold of a certain plant, it can seem like the botanic gardens are trying to keep all the best material for themselves, but the reality is that if they do not abide by the conditions under which they were allowed to collect, they will not be allowed to collect in that location again, and they would be breaking the law. To put it simply, you cannot visit a country and dig up plants or collect seed without the permission of that country, in just the same way you shouldn’t (and I hope, wouldn’t) go into someone else’s garden and take plants for your own garden without the agreement of the owner. This is probably the only aspect of plant hunting that was a lot more simple in the past. Digging up plants and sending them home, even if only a small percentage survived, was commonplace but today’s legislation aims to prevent this. After all, it is the plants that


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need protection, not the plant hunters. Nevertheless, done properly, sustainably, with the right permissions granted and with respect for natural habitats and wild populations, plant hunting continues to reward botanists and horticulturists with new plants and furthers our understanding of the world’s flora.

Plant naming Plant names follow the binomial system invented in the eighteenth century by Swedish naturalist Carl (or Carolus) Linnaeus. Each name is in two parts, the name of the genus and that specific to the species. In 1753, Linnaeus published Species Plantarum, in which he described all the plants known to him and named them using a genus and species. Before this, plant species often had long descriptive names in Latin, usually consisting of several words. Linnaeus simplified matters by bringing similar plants together under one genus name and by giving each one an individual species name.

Nowadays, a species name is only valid if it is published in a recognised publication together with a Latin description of the species. An herbarium specimen must be taken and this is called the type specimen. The location where the type specimen was growing in the wild is called the type locality. Even if a name is validly published, it may not be accepted by the scientific community. Joseph Hooker described the Spanish Draba mawii in 1875, but subsequent publications treated this plant as a variety or subspecies of D. dedeana, a plant previously described by Boissier and Reuter in 1845. More recently, D. mawii has been reduced to a mere synonym of D. dedeana. In the following chapters, there are plenty of examples of plant species that have had two or more names since they were first described. As we increase our understanding of how plants have evolved, how they vary across their natural range and how different plants are related to each other, in particular by studying their DNA, name changes are inevitable and necessary.

above left A low-growing willow, Salix reticulata, forms a spreading mat in the mountains of Norway.

above right Androsace muscoidea sheltering in the rock crevice at 4,275 m above sea level, in the Indian Himalaya. Photo: Joanne Everson.

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Alpines - Intoduction