Ethnobotanical gardens - Lamarck

People have always used various plant species for food and medicine. Plants have also been used in agricultural, artisanal and religious practices. This square showcases plants that are useful to mankind. In fact, ecology teaches us that all species are useful, because they play a role in nature as they interact with each other as well as with animals and insects.

When it was founded in 1635, the Jardin des Plantes was originally created for the purpose of producing medicinal plants for the king. With the development of botany in the 18th century, the Garden's scientists aspired to present an inventory of all of nature’s plants there.

Ethnobotany, which studies the relationship between human societies and the plant world, is one of the disciplines carried out at the Museum, through herbariums, cultivated plants, seed banks, etc.

On the map:

1. cultivated plants through the ages
2. medicinal plants
3. plants and technology

Plants have followed humans in their migrations, growing wherever they could, adapting to new soil and climate conditions, usage and changes in culture. This part of the Garden displays plants that have been cultivated successively in France, particularly for food, from the Neolithic period (6000 BC) to the present day. How they have been domesticated, adapted and disseminated over time is known thanks to the research of archaeologists, historians and geneticists continuing the work of A.G. Haudricourt (1911-1996), the Museum’s agronomist, ethnobotanist and linguist. Each bed presents the diversity of crops at different periods of our history, newly introduced species and those at their peak: cereals (wheat, barley, millets, triticale...), legumes (lentils, peas), vegetables, oilseeds (flax, poppy, sunflower) etc.

Domesticated 12,000 years ago in the Near East, new plants arrive in southern France around 5800-5500 BC and in the northern half around 5200-5100 BC.

The cultivation of these plants and livestock practices open up clearings in the forests and begin to change the landscape.

Dressed wheat (starch, einkorn, small spelt), naked wheat (durum, common wheat), pulses (peas, lentils) and oilseed (flax) are now being grown.

The sleeping poppy may have been domesticated in Western Europe during this period.

The Atlantic coast, the north of the Alps and the Mediterranean play a significant role in cultural exchanges.

In the countryside, farms are grouped into hamlets or networks. Crops are grown intensively and include a rich diversity of cereals, legumes, fibrous plants, dye plants and oil-rich species. The fields are regularly fertilised and several species can be grown together on the same plot of land.

New plants are introduced or spread via the Alps: spelt wheat, millets, einkorn and broad beans; camelina becomes an important oilseed. Barley is grown and diversifies. Foraging plants include acorns, hazelnuts and native apples.

During the two Iron Ages, societies become more complex. Urbanisation occurs earlier in southern Gaul than in northern Gaul. A number of technical innovations are introduced: the scythe diversifies sources of fodder, the rotary mill facilitates the processing of cereals. The Iron Age ends with the conquest of Gaul and the rise of the Roman Empire. Farmers specialise in starch and barley in the north, spelt in the north-east and naked wheat and barley in the south. In all areas of the country, millet is in decline. Oats are occasionally grown in the northwest. In the Greek colonies of the south, figs, almonds and pomegranates are sold, the first vineyards appear and olive cultivation loses its importance.

Rome increasingly controls trade between southern Gaul and the Mediterranean, competing with Greek influence. The territorial organisation of Gaul into cities dominated by a capital city is established under Augustus, with the beginning of the Empire (27 BC - 14 AD).

Production systems adapt to the increasing urbanisation and reorganisation of trade that spans as far as India and the Far East.

Responding to changing tastes and culinary practices due to cultural shifts, new plants are added to gardens and orchards (savory, peach, walnut, plum, domestic apple and pear trees, fig trees, etc.), while exotic plants (cumin, sesame, pepper, rice, dates, jujube, etc.) are imported.

Society in the Middle Ages, especially among peasants, changes under the influence of Christianity and the arrival of new settlers. Towns and castles spring up. The need for cultivated land and wood shrinks the forest and the landscape changes: bocage, salt marshes, mills. The number of craftsmen and kinds of artisanship are on the rise: blacksmiths, weavers, farriers, millers. Merchants offer new foodstuffs from Africa and the East: rice, sorghum, spinach, aubergine, sugar and durum wheat pasta. Archaeobotanical data has revealed the decisive Arab role in the introduction of these foodstuffs, negating the importance of the Crusades. Rye and oats became more widespread, and fruit and vegetable varieties are introduced in the gardens of the secular and religious elites.

The period between Christopher Columbus's expeditions to the Americas and the end of the 18^th century is characterised by the arrival of new crops in Europe (corn, cucurbits, tomatoes, potatoes, beans, etc.) which had not yet replaced local plants, but would nevertheless diversify crops, even if these introductions would be confined to the gardens of the elites before being disseminated into agricultural systems. The creation of gardens near trading posts established on sea routes encourages the distribution of exotic plants brought back to Europe. Some are viewed with suspicion (tomatoes, potatoes), while American beans soon become popular. The dahlia is introduced to gardens in 1788 for its edible tubers.

In the past, farmers would select their seeds on the farm, thereby ensuring genetic diversity. With industrial and commercial development, population growth and advances in agronomy in the 19^th century, seed companies create more effective varieties of plants. The introduction of the railway shortens transportation times and facilitates regional specialisation (artichokes in Brittany, tomatoes in Provence, etc.). "Country wheats" are replaced by improved varieties. Tropical agronomy and plant exchanges between trial and acclimatisation gardens in the colonies and in metropolitan France start to appear. These days, some ancient wheats still exist and there is a renewed interest in organic farming.

Of the 300,000 known plant species in the world, just 30 of them cover nearly 95% of humanity's food needs. Although cultivated food plants have diversified enormously since the expeditions around the world, a number of them have pretty much been abandoned, such as tuberous-rooted chervil, alexanders and arrowroot. This may be due to changing tastes, which would also explain the renewed interest in certain other vegetables. Some plants, which were commonly consumed during the Second World War (Jerusalem artichoke, rutabaga), suffered from being associated with food rationing and disappeared from plates, only to reappear recently. A taste for so-called "terroir" products is coming back into fashion and older varieties of vegetables that were pretty much forgotten about or less well known are making a comeback.

The plant world provides human beings with many resources, whether it is for food, clothing, health care, building materials, various tools for work and leisure, or as a source of technological or cultural inspiration.

These resources are plentiful throughout the world and the study of these relationships between plants and humans is ethnobotany, which is one of the many disciplines studied at the Museum.

In many regions, hedges mark the boundaries of fields. Composed of a huge diversity of plants, hedges are the result of forest clearances through the years and form a landscape known as bocage. Many benefits have been derived from having these hedges: they keep livestock contained, and the regularly pruned trees provide fodder for the animals as well as wood for baking bread or making tools. Hedges also mark out property boundaries. After the Second World War, the development of agricultural mechanisation and the invention of barbed wire resulted in the destruction of many hedges. Today, they are once again being used to combat soil erosion, promote more environmentally friendly farming practices and encourage biodiversity by providing a refuge for birds and insects.

Sometimes young tree branches are bent and intertwined horizontally with twigs and left to grow vertically: this is called laying. Plaited hedges have now almost disappeared from the rural landscape, swept away by intensive and mechanised agriculture. This particular form of bocage involves a lot of manual work. However, in the West, the North and the Centre of France, associations have been busy reviving it, providing training for some twenty years. Regional nature parks, local authorities and landscape gardeners use the laying technique, but the people doing it have changed, along with their aims: laying is no longer just an agricultural activity, it has become more about protecting heritage (the conservation of countryside hedgerows), the ecology (species diversity) and scenic landscapes.

Plaited hedges delimit certain areas of the Jardin des Plantes' ecological garden.

The earliest evidence of the use of fibrous plants for textiles and basketry dates back more than 10,000 years; those for paper to about 2,000 years. These plants contain cellulose. Fibres come from stems (hemp, flax, jute, nettle, ramie, reed, willow, etc.), leaves (sisal, dwarf palm), seeds (cotton, kapok), fruit (coconut), and bast (under the bark of linden and oak trees). These fibrous plants can be used in their natural colours or dyed other colours for symbolic reasons or according to fashion tastes. Until the 19^th century, dyes were made with natural colourants from animals (cochineal etc.), or using minerals (ochre) and plants (leaves, roots, berries, wood etc.). Many plants contain pigments in their various parts (flowers, leaves, roots). They are also used in paints, food, cosmetics, etc.

Humans have always tried to reproduce the colours they see in nature. Until the 19^th century, dyes were made with natural colourants from animals (cochineal etc.), or using minerals (ochre) and plants (leaves, roots, berries, wood etc.). Plants that can be used as dyes played an important economic role from the 17^th to the 19^th century; thousands of tons of dying products were imported into Europe each year from America and Asia.

In France, from the Middle Ages until the arrival of exotic plants such as indigo – and then with the development of chemical dyes – certain regions specialised in the cultivation of dyes (dyer’s weed in Languedoc-Roussillon, dyer's madder in Vaucluse and woad in Albi and Picardy).

In China, blue can herald death; in India, it is the colour of mourning; among the Romans, it was associated with barbarians... It was not until the 12^th century that this colour was valued and admired: Saint Louis chose blue decorated with golden fleurs-de-lys as the colour of the King of France. Back then, the blue pigment came from woad, which was later replaced by indigo. Both of these plants produce their dye once macerated in water and through oxidation when brought into contact with the air.

The colour of choice in all civilisations, red symbolises blood, strength, power and fertility. A colouring molecule, alizarin – which was very much sought after in the Roman Empire before seeing a decline in popularity in the West – is extracted from the root of the dyer's madder. In France, it was Colbert who would bring it back into fashion. Here, we recall the "garance trousers" of the French army during the wars of 1870 and early 1914.

In the Middle Ages, yellow is discredited in both Christianity and the Muslim world, where it is associated with treachery.

In India, however, it is worn at weddings and in China it is the colour of robes worn by the emperor and Buddhist monks.

Many plants produce shades of yellow, but few dyes can withstand light and washing. This explains the bluish colour of the greens on medieval tapestries that have been on display for a long time.

The earliest evidence of the use of fibrous plants for textiles (from yarn to fabric) and basketry (baskets, mats, hats, etc.) dates back more than 10,000  years; those for paper to about 2,000 years. These fibrous plants all contain cellulose, an organic molecule made up of glucose and structured as microfibrils, which is extractable to varying degrees.

The fibres come from:

• stems: hemp, flax, jute, rush, nettle, ramie, Spanish broom, reed, willow (wicker);
• leaves: sisal, dwarf palm; seeds: kapok, cotton (the fibre is composed of almost pure cellulose);
• fruit: coconut;
• bast (under the bark of linden and oak trees).

Distillation is discovered in the Middle Ages and, during the Renaissance, ethanol is discovered by means of cooling using the alembic still. Perfumes are used first as a medical remedy, then to camouflage odours. From the middle of the 19^th century, the development of the chemical industry and synthetic products made perfumes more available to the masses. Different parts of the plant are used, depending on which plant they come from: rose (petals), sage (leaves), lavender (leaves and flowers), lemon trees (fruit), coriander (seeds), camphor (bark), cedar (wood), myrrh (gum), iris (parts that grow underground), etc.

The seven olfactory families: citrus (hesperidin), floral, wood, chypre, amber, fern and leather.

An essential oil is a liquid mixture of molecules obtained from a plant or parts of a plant. It is a non-greasy liquid, its constituents are volatile, odoriferous, lipophilic (soluble in alcohol and in fat) and insoluble in water. Essential oils are mainly terpenes (limonene in lemons), varying degrees of oxygenated derivatives (menthol, camphor) and phenolic acids (methyl salicylate). They are classified into three categories: cosmetics, biocides and medicines.

Using them for self-medication is advised against. Some are only to be used by pharmacists (dill). Examples of organ damage (liver), impairment of the nervous system, and drug contraindications (St John's wort) have been reported.

Aromatic plants are fragrant and mainly used as condiments to enhance the taste of food. Rich in essential oils, these plants give off aromas that are widely used in cooking, perfumery or for their activities in phytotherapy.

Depending on the plant, different parts are used: leaves, stems, bulbs, roots, seeds, flowers, bark…

Aromatic plants have been gathered and cultivated for thousands of years, as evidenced by papyri and engravings in Egyptian tombs (cumin, coriander, mint, etc.).

In the Middle Ages, Charlemagne encouraged the cultivation of sage, rosemary and fennel. The monks would tend to a "garden of simples" (herb garden) in their monasteries. Most aromatic plants or "fines herbes" have medicinal virtues that were known to the ancients and have since been confirmed by chemical research.

Ethnobotanical observations have also shown that there are traditional practices of protecting crops against insect pests with scented species.

From time immemorial, human beings have worked with plants, picking them, pruning them, domesticating them. In doing so, they have designed and shaped landscapes according to how they have used, selected and exploited their environment. By clearing forests to open up new cropland, they have retained species that were useful to them in the hedgerows along field boundaries. On sloping land, they have built terraces. They have removed stones from rocky soils, built low walls, and even cultivated soils... In agricultural practices, certain plants are used to enrich the fields, kill pests and limit soil erosion.

Their insecticidal, fertilising and cleansing properties result from the action of several chemical compounds, the use of which can contribute to diverse plant pest control methods and the purification of polluted soils.

You can make your own insecticides, insect repellents, acaricides, fungicides and plant stimulants for the garden. The shelf life of each product will differ according to the method used. For use against pests, the active ingredients of these products can either be extracted in hot water by infusion or decoction, with cold water by maceration, or used as a slurry. Whichever way you choose, it is recommended that rainwater be used and that treatments are applied as a spray. Nettle manure, for example, is not only a fungicide and an insecticide, it is above all a fertiliser that is rich in nitrogen, and acts by stimulating plant growth. Like tansy, common wormwood repels harmful insects (flea beetles, cabbage worms...).

Fruits, vegetables and herbs grow better if they are in the company of other plants with which they have an affinity. By complementing each other, these combinations make the vegetable garden more productive by keeping pests away and limiting diseases.

They reduce the need for synthetic pesticides and fertilisers. Carrot and tomato, leek and strawberry, basil and cucumber, bean and dill, lavender and rose, these friendly plants protect each other.

Soil that is always planted with crops, green manure or compost is easier to cultivate.

Everybody wins!

Many plants are used as green manure. By quickly occupying the space left empty after a harvest, these intermediate crops limit weed growth and enrich the soil with the atmospheric nitrogen that they capture. They protect against erosion and retain soil elements, thereby limiting the phenomenon of "leaching", which carries certain pollutants to the water table. They also loosen the earth, thereby improving its structure and feeding soil fauna.

Phytotechnologies use plants to extract, contain or break down pollutants: these plants are grown on agricultural lands, industrial wastelands, mining sites or in polluted waters. In cities, they help to restore nature on polluted land.

In some cases, plants or micro-organisms living at root level absorb and break down pollutants (e.g. pagoda dogwood and marsh bulrush break down hydrocarbons).

In other cases, they accumulate them in their leaves and are then harvested and burned. The long-leaved fern absorbs arsenic, the wall fern nickel and the broad-leaved club zinc.

Human beings have always looked to their environment for ways to look after themselves. Many of the medicines used today come directly or indirectly from plants whose medicinal properties have been known for a long time.

From the Middle Ages onwards, the "garden of simples" (herb garden) became popular. While the virtues of some plants were known, they would sometimes be used according to how their shape or colour resembled the organs to be treated. This followed the doctrine of signatures, which was inherited from Greek antiquity. Advances in chemistry in the 19^th century made it possible to identify the active ingredients that the plants produced, which would go on to constitute modern therapeutics.

Today, research into new active ingredients is based on synthetic products, compounds and natural extracts obtained in state-run laboratories, such as those at the Museum.

The molecules involved in cardiotonic activity are heterosides made up of several oses (sugars) and a steroid (cholesterol skeleton).

Only those of the woolly foxglove (such as digoxin) and the purple foxglove (such as digitoxin) are used. But beware, they can quickly become toxic if the dose is not sufficiently adjusted! For this reason, the plants that produce them are never used "in their natural state".

This type of molecule is only ever administered under medical supervision. Symptoms of intoxication are vomiting, nausea and intestinal pain.

Other plants produce the same type of molecules, but these are very toxic, such as oleander, lily of the valley and hellebore.

Some plants have been shown to be effective in the treatment of benign lung conditions. Active ingredients are obtained by extraction or via the plant’s essential oil. They act by calming coughs and inflammation of the respiratory tract and facilitate expectoration.

• Acidic mucilages (polysaccharides) are softening and emollient due to their viscosity (marshmallow, linden, mullein, etc.);
• terpene saponins protect the mucous membranes (hyssop, primrose, ivy, etc.);
• flavonoid derivatives (liquiritin) inhibit the cough reflex (liquorice);
• terpenes are antiseptics that treat rhinitis (thyme) and relax the respiratory tract (mint).

The plants used in dermatology act by combining the diverse effects of the molecules they produce. Their tannins make them astringent, but they also have other effects:

• Burdock, which is used in the treatment of acne and eczema, limits bacterial growth.
• Marigolds produce terpenes with anti-inflammatory properties that help to combat dermatitis brought on by radiotherapy.
• Yarrow has an anti-inflammatory effect and is recommended for skin inflammations.
• Primrose is commonly used to treat bruises through the action of its saponins. Caution: horticultural varieties can cause hives!

Herbs can have an effect in the treatment of constipation, with two kinds of laxatives:

• Ballast laxatives, which modify the consistency of the stools, consisting of mucilage (psyllium) or fibres (flax). These molecules can interact with drugs and alter how they are absorbed.
• Laxatives that stimulate the intestines. The plants in question (borage, rhubarb, buckthorn) act by inhibiting fluid reabsorption and stimulating intestinal contractions. Since these molecules can also cause heart problems, it is imperative that these plants not be consumed without first seeking medical advice.

Lipids are derivatives of fatty acids, which is the reason why they are hydrophobic (they are water repellent). They constitute an energy reserve, have roles in cell communication and form biological membranes. Some fatty acids are called "essential" because they are not biosynthesised by mammals. Instead, they have to be provided by one’s diet (unsaturated fatty acids present in certain seeds and their oils: linolenic acid or omega-3 – flax, rapeseed, hemp, soya and walnut – and linoleic acid or omega-6 – peanuts, wheat germ, corn and sunflower). The most abundant fatty acid in nature is oleic acid (from oleum: oil), which is the main component of olive oil. Trans fatty acids, the consumption of which increases cardiovascular risks, are found in processed foods.

Certain plants can be used to combat various mouth ailments:

• bleeding gums, thanks to tannins and their astringent properties (geraniums), and flavonoids with coagulant properties (bistorta and loosestrife);
• mouth ulcers, thanks to these same properties, which are associated with anti-inflammatory properties due to triterpenes (geranium, bistort, rose, horse chestnut);
• infections, thanks to antimicrobials such as allantoin (a degradation by-product of two of the four DNA bases), which is present in some toothpastes (comfrey), gallic acid (bistort) and terpenes (geranium).

Some plants produce active ingredients that are beneficial in the treatment of temporary mood and sleep disorders. These molecules act on nerve transmissions, such as hyperforin from St. John's wort (mood and mild depression) and valerenic acid (sleep). A molecule extracted from the snowdrop, galantamine, is used in the treatment of Alzheimer's disease, but its mode of action can cause numerous side effects. Until 2016, vincamine extracted from myrtle was prescribed for the treatment of pathological cognitive impairment in the elderly.

Two major molecule families with analgesic effects are extracted or derived from molecules produced by plants:

• Salicylates: salicyline, a derivative of salicylic acid, is extracted from willow and spiric (or salicylic) acid from meadowsweet to produce aspirin. Other plants produce salicylates: wintergreen, beech, birch, coffee, liquorice, olive.
• Morphinans are alkaloids produced by plants of the Papaver genus. The latex of the poppy (P. somniferum var. album) yields opium from which morphine, codeine and thebaine are extracted, while the poppy (P. somniferum var. nigrum) is cultivated for its flowers and oil (food and paint).

Some of the molecules that are responsible for the colours of flowers and fruits can help vision in the case of circulatory disorders in the retina, and for the regeneration of retinal pigments. The blue, red, mauve and purple colours are mainly due to molecules of the anthocyanoside family (from anthos: 'flower', and kuanos: blue), made up of sugars and flavonoids whose colour depends on the acidity of the soil. Plants containing carotenes, such as carrots, also promote the regeneration of eye pigments. They are also said to improve night vision (Gls ate blueberries during the war), but their effectiveness has not been proven. Thanks to these molecules, these plants are used as colouring agents in food.

Some plants produce molecules that can control haemostasis:

• Either as an antiplatelet agent: salicylate derivatives (aspirin) from willow or meadowsweet, sulphur products (ajoene) from garlic, terpenes from camomile.
• Or as an anticoagulant: coumarin derivatives in sweet clover, sweet woodruff or horse chestnut, which are formed under certain storage conditions. These molecules act by inhibiting the action of vitamin K.

Conversely, some plants produce vitamin K and using them can reduce or even eliminate the effectiveness of anticoagulant treatment: cabbage, spinach, nettle, parsley, coriander.

Some plants improve blood circulation by toning the blood vessels and stimulating venous return. They help to combat the feeling of heavy legs. Several families of molecules are involved:

• tannins from dried leaves (witch hazel, hawthorn, grapevine), cone powder (cypress) and grape seeds exert a vasoconstrictive effect by means of their interaction with proteins;
• steroidal saponosides (ruscogenin from fragon) and triterpenic saponosides (aescin from horse chestnut) improve the contractility of venous smooth muscle;
• anthocyanins from blackcurrants, bilberries and grapevines reduce vessel permeability, but this effect may also be due to flavonoids.

In France, diarrhoea is mainly viral in origin and antibiotics are not effective. Some plants can act effectively thanks to the tannins they contain (these are astringent molecules that cause tissue contraction):

• lady's mantles, agrimony, bramble and hazel, whose leaves are made into a tea;
• strawberry bush, used by decoction of dried rhizomes;
• fruits such as blackcurrants and blueberries, which can be consumed as they are or in the form of a juice.

It is recommended that certain foods be eaten (cereals, carrots, bananas, cooked fruits, meat, eggs and fish, mashed potatoes), and others be avoided (dairy products, raw fruits, green vegetables). Drinking water regularly is also important, to avoid dehydration.

Oxygen is essential for life, but derivatives of oxygen (which are natural products of metabolism) can, in high concentrations, have harmful effects on cell structures, especially DNA, and accelerate ageing.

Molecules called "antioxidants" help to combat these effects: vitamins C and E, carotenoids (lutein and lycopene), flavonoids contained in many fruits (goji berries, blueberries, blackberries, raspberries, strawberries, prunes), coloured vegetables (peppers, red cabbage, beetroot, artichoke, etc.), and legumes.

Studies have shown that the intake of antioxidants through food supplements may be beneficial against the risk of cancer, but not very effective against the effects of ageing.

Molecules produced by plants are used to fight bacteria, fungi and parasites, with internal and/or external uses:

• antimicrobial sulphur derivatives: nasturtium flowers used against respiratory and urinary tract infections; broccoli and cauliflower against Helicobacter pylori bacteria, which is common in the digestive system;
• organosulfur compounds in garlic: some are antibiotic, others are vermifuge;
• hydroquinone: present in bearberry or cranberry leaves, it is an antibacterial of the urinary tract;
• artemisinin: an antimalarial drug produced by the annual mugwort plant;
• cucurbitin: contained in pumpkin seeds, active against tapeworms.

The anti-cancer action of molecules isolated from plants involve various modes of action. They belong to different families:

• Navelbine isolated from the Madagascar periwinkle is an alkaloid that is pharmacologically interesting at low doses, but toxic and even lethal at high doses.
• Taxanes, of which paclitaxel isolated from yew (Taxus) is a terpene.
• The podophyllotoxin isolated from Podophyllum hexandrum is a lignan. Obtained in small quantities, it is produced from podophyllin extracted from the American podophyll (Podophyllum peltatum).
• Turmeric, a polyphenol isolated from Curcuma longa, combined with conventional treatments, is believed to slow down the development of certain cancers.

Plant extracts can act on the liver in two ways:

• to treat digestive disorders, by promoting bile flow and increasing the secretion of bile acids (artichoke or dandelion extracts);
• through hepatoprotective activity (action of silybin, flavonoid contained in milk thistle).

Several plants have diuretic properties, such as hawkweed (Pilosella officinarum), thanks to its flavonoids (luteoside), or help fight against kidney stones, such as couch grass (Triticum repens).