The Clusius Garden
Hortus botanicus, Leiden



One of the most important developments at the European universities in the 16th century was the gathering of medicinal and toxic plants in a special garden, a Hortus Medicus or medicinal garden. Such collections served as reference collections and instruction material for the medical students. The first Hortus Medicus was founded at the University of Pisa in Italy in 1543. Not long afterwards the universities of Padua, Florence, Bologna and Leipzig followed.

The University of Leiden also desired a medicinal garden and in 1587 decided to allot a 'ledige plaetse' (empty space) behind the Academy building at the Rapenburg for a 'Cruydhof' (herb garden). Although the Hortus Academicus Lugduno-Batavus (garden of the University of Leiden) was founded on 9 February 1590, it was not till 1594 before the first planting was ready. For the design of the new garden a famous botanist with a great plant collection was sought. Discussions on the position of Praefectus Horti (director of the garden) were held with Bernardus Paludanus (ca. 1550-1633), doctor and herbalist in Enkhuizen, but in the end he did not come to Leiden. Thereupon the position was offered to the most famous botanist of the time: Carolus Clusius.


Carolus Clusius

Charles de l'Ecluse, better known as Carolus Clusius, was born in 1526 in Atrecht (modern-day Arras). Clusius studied law and classical languages in Leuven, medicine in Montpellier and attended lectures on many various subjects in many different European cities. In 1554 he returned to the Netherlands. There he made his acquaintance with the famous town-doctor of Mechelen, Rembertus Dodoens (Dodonaeus), the doctor and botanist Matthias de l'Obel (Lobelius) and the printer Christoffel Plantijn from Antwerp. In 1561 Clusius began his duties as mentor to noble and well-off youths. He travelled through England, France, Spain and Portugal with his pupils, collecting plants and studying them as he went. In 1573 he left for Vienna to design a garden with medicinal herbs for the Emperor Maximilian II. During his stay in the Austrian capital, Clusius created a fabulous collection of rare and exotic herbs, notably specimens from the Alps and bulbous plants from Turkey. The bulbous plants, among which tulips, hyacinths, crown imperials and daffodils, he also managed to acquire with the help of the emissaries of the Emperor to the Court of the Sultan in Istanbul. He left Vienna in 1588 and settled in Frankfurt. In 1592 the University of Leiden offered him the position of Praefectus Horti and in the autumn of 1593 Clusius arrived with his plant collection in Leiden, 67 years old and in bad health.

(Carolus Clusius from J.J. Boissard, 1598)

Clusius and botany
The publication of Clusius' Rariorum aliquot stirpium per Hispania observatorium Historia (Flora of Spain, 1576) was an important event for descriptive botany. In this book he broke with the prevailing method of describing plants on the basis of their supposed beneficial or harmful properties. Clusius was not especially interested in medicinal herbs; he studied plants out of his own curiosity. Moreover, he described plants from a certain area: he created the 'flora'. He strove to give every plant a name that consisted of two parts, e.g. Rosa centifolia, and sometimes even added the personal name of the person who had earlier mentioned said plant under that name.

Of every plant, branches, leaves, flowers, fruit and seeds were meticulously described. Clusius provided information concerning color, scent and taste, the conditions under which the plant grows, the colloquial names, the industrial, medicinal and domestic uses and finally the literature in which the plant had been mentioned before. The Appendix of the Spanish Flora is of great importance. In this part, various plants from Turkey are described, like tulips and other bulbous plants, anemones and ranunculi. In the 16th century these were still strange and exotic in Europe.

In Clusius' later works the emphasis came to lie ever more on the scientific description of the characteristics of the plant and less on its use. Rariorum aliquot Stirpium, per Pannonium, Austriam,enz (Flora of Austria and Hungaria, 1583), Rariorum plantarum Historia (1601) and Exoticorum Libri Decem (1605), the first and second parts of his collected works, respectively have become world-famous. All these books were published by Plantijn and were illuminated with splendid woodprints.


The garden of Clusius: the very first lay-out of the Hortus

To assist Carolus Clusius with the design of the new university garden of Leiden, the pharmacist Dirk Ougaertszoon Cluyt (Clutius) from Delft was appointed Hortulanus. Cluyt was the author of the first Dutch book on apiculture and was a great expert on medicinal herbs. He took his own collection of such plants along with him to Leiden. In 1594 the first lay-out was completed. Clusius and Cluyt made a plan of this situation with a list of plants that grew in the new Hortus at that moment. Through this manuscript, the Index Stirpium, one may get a detailed image of the original Leiden Hortus. In 1594 was de eerste aanleg gereed. Clusius en Cluyt maakten van deze situatie een plattegrond met een lijst van planten die op dat moment in de jonge Hortus groeiden. The garden was rectangular: 39,90 m in length and 30,90 m wide. The proportion length : width was 4:3, one of the classical harmonic proportions of the Italian renaissance. At the South side a gallery was built in 1600, the Ambulacrum, where a great collection of animal, botanical, geological and ethnological material was exhibited in an orderly fashion. In this building, the professor in botany also gave lectures and plants that were sensitive to the frost were kept in winter. Two main paths divided the garden itself into four quadrae, each consisting of 16 or 12 areae. Within each quadra four groups of areae were created by two narrower paths. Each area was subdivided into many pulvilli, in which one species of plant was assigned per pulvillus.

(Plan of the Hortus in 1594)

(The Hortus in 1610. Sketch by I.C. Woudanus)

The plants
The inventory of 1594 mentions 1070 plant names in the beds and along the walls 171 species were planted in pots or elsewhere. The exact number is difficult to determine, because one group of plants is often designated with one name, e.g. Tulipa serotina diversorum generum (several kinds of late-flowering tulips) or Irides marinae selectorum colorum (several colors Iris marinae). Besides the traditional medicinal, poisonous and other beneficial plants there were a great number of well-known ornamental plants. Extremely interesting are the many wild species and ornamental plants from the Mediterranean, the Middle East and America. A great number of these garden plants that are so well-known today originally hail from these parts and were introduced to the gardens of North-Western Europe by Clusius and the Hortus of Leiden , e.g. tulips, hyacinths, crown imperials, anemones and horse chestnuts. The presence of potatoes, tomatoes, ginger, ocra, sugarcane and elephant ear is remarkable.

That Clusius had distinct views on groupings in the plant kingdom becomes clear from the fact that in quadra I, II and IV plants that according to him are related are gathered together in the areae. For example, in quadra I, area 3 various species and varieties of peonies were planted, in quadra I, area 2, 4, 6 and 8 bulbous plants, in quadra II, area 1 various species of artemisia, in area 4 roses and in quadra IV, area 8 Boraginaceae species. Quadra III was not ordered systematically and the plants were set very closely together. One gets the impression that these plants had not yet been completely described and grouped. Among this group is the fine collection of wild plants from Crete, which Clusius had acquired via de botanical garden of Pisa, among others.

On the short sides of the areae in quadra I there were borders of small plants: on the outer side pasque flowers (Pulsatilla vulgaris) and Cortusa matthioli and along the main path, dwarf irises.
The areae 6 and 12 of quadra II were planted with broad-leaved and narrow-leaved irises, respectively; together with the opposite border of dwarf irises they created an 'iris-lane' along the main path.

In several cases trees and shrubs rise out of the center of the area, e.g. quadra II, area 12 a Phyllirea among the irises. These small trees were very probably pruned as globes or in levels. Sometimes the area is partly empty (e.g. quadra II, area 16); this merely indicates that in 1594 nothing grew on the spot. In following years these spaces do seem to have been filled in.

In quadra I, the areae 2, 4, 6 and 8 are surrounded by a sturdy fence with a gate. Very probably this gate was supposed to protect the rare bulbs that grew there against vandalism and theft.

The tulip (Tulipa spp.)
The tulips that Clusius received from Turkey were popular garden plants in those areas. He arranged these garden-tulips in two groups, nl. Praecoces and Serotinae , resp. early- and late-flowering tulips. Intermediate forms were placed in a rest-group, Dubiae. Clusius performed sowing tests and noted that: 'Seeds from the same fruit, which I myself collected and at the same time put into the earth in the autumn, have in the next spring produced some sprouts, which after the 5th till the 10th year (for some develop quicker than others) produced white, spotted white, yellow, spotted yellow, red, spotted red, purple and spotted purple tulips.'


He provides us with an extremely accurate description of the development and culture of the tulip and finally mentions: 'A merchant from Antwerp received along with a shipment of cotton cloth from Constantinopel some tulip bulbs; he mistaked them for onions and ate some roasted with vinegar and oil. The remainder he threw into his garden among various kitchen waste. By accident these bulbs were noticed by a merchant from Mechelen named George Rye, who was well versed in botany; he took them with him and planted them in his garden and it was thanks to this that I was later able to see various new varieties.'

The Canary Islands Dragon Tree (Dracaena draco L.)
Clusius first saw a specimen in Lisbon. He described the plant as Draco arbor in 1576 in the Flora of Spain. Dragon Trees belong to the family of the Lilies (Liliaceae) and can become very old. This species is native to the Canary Islands. From the trunks a reddisch resin will flow, the so-called dragon’s blood, which was used in medicine.

The potato (Solanum tuberosum L.)
Clusius received two bulbs and some seeds of the potato plant on 26 January 1588 from Philippe de Sivry, Lord of Walhain and governor of Mons in Henegouwen. A year earlier De Sivry received this new plant from the papal legate in the Southern Netherlands under the name Taratoufli. Clusius made the first scientific description of the potato in his Rariorum Plantarum Historia in 1601 under the name Arachidna; in the inventory of 1594 it is called Papas Americanorum.
In the wild the potato grows high in the mountains of Central Mexico, and from Peru to Bolivia and so thrives in a cool climate. The Spanish conquerors took this tuberous plant back to their homeland around the middle of the 16th century. From Spain the potato was introduced to other European countries, but only around 1750 did it become a popular food.

The hundred-petaled rose (Rosa centifolia L.) The hundred-petaled rose belongs to a small group of garden roses that was probably developed in the 16th century in the Netherlands. The first scientific description was made by Clusius in his Rariorum Plantarum Historia (1601) as Rosa centifolia batavica. In 1589 Clusius received two rose bushes from his friend Johan van Hogheland. One bush survived and flowered in 1591 in Leiden with very plump, pink, strongly fragrant flowers. Van Hogheland sent another rose bush in 1592 to Leiden. Clusius never saw this plant flower and in the Rariorum it is indicated as Rosa centifolia batavica II (altera). According to Van Hogheland it was identical to number I, but smaller. The hundred-petaled rose was extremely popular with the floral painters in the Low Countries. One of the most famous illustrations is an aquarelle by the painter Jacques de Gheyn II from 1603. Nowadays we are glad to see the pleasing hundred-petaled roses growing again in the gardens of true rose enthusiasts.

The reconstruction of 1932
In 1931 the then Praefectus Horti and Hortulanus, Prof. dr. L.G.M. Baas Becking and H. Veendorp, decided to reconstruct the original Leiden Hortus. As a startingpoint they used the Index Stirpium of 1594. Their first task was to find out which plants belonged with the names used by Clusius and Cluyt.

Such an interpretation proved much more difficult than it at first appeared, because our modern plant names hail back to the publications of Linnaeus from 1753. All plant names used before that time are not valid or are designated 'pre-Linnean'. Much patient detective work had to be done before could be decided on which plants were meant exactly. The design of the garden was understandably not easy.

The original 'ledighe plaetse' behind the Academiegebouw was rendered almost unrecognizable by centuries of building and by the presence of an enormous brown beech from 1819. Eventually the garden of, the Hortus Clusianus, was reconstructed on a piece of ground next to the old Collegium Theologicum at the 5th Binnenvestgracht. This parcel was only about two-thirds the size as Clusius’ garden, making the reconstruction proportionally smaller. The areae were provided with brick borders; in 1594 the beds were probably just raised as low dikes. The paths were covered with a layer of shells. And although such shell-covered paths were not uncommon in 16th century Dutch gardens, in the first years of the Leiden Hortus the paths were covered with processed oak-bark from local tanneries. No attempt was made to prune or cultivate in the 16th century manner.

In the next 55 years the woody shrubs grew into sturdy trees, many tender plants were overgrown by their sturdier neighbours and some species disappeared from the garden.


The reconstruction of 1990
In 1986 a Praefectus Horti and his Hortulanus again decided to tackle the garden of Clusius. Just as in 1932 the Index Stirpium of 1594 was chosen as the starting point and the interpretation of Clusius' plant names became the central problem. Fortunately, this time there were two new sources of evidence available: in 1974 the famous Libri Picturati, the aquarelles of plants that were painted by order of Clusius and Plantijn and served as model for the woodblock prints, were re-discovered in the Jagiellon library of the University of Krakow in Poland. These fabulous illustrations show the exact colors of the flowers and many other details. And they are also provided with the plant names of the time. Also the herbarium of the Leiden pharmacist Antoni Gaymans, made between 1660 and 1680 from plant material from the Hortus was re-discovered. The plants in this collection, the oldest known Dutch herbarium, are provided with the 17th century names. By means of the dried material it could be determined how to link the old names to existing plants.

Tracing the correct specimens of living plants was not an easy task. Approximately 70% of the species and varieties from 1594 were still available. Certain wild species were hard to come by, e.g. the plants from Crete. Most of the 16th century garden varieties of, for example primroses, columbines, peonies, roses and bulbous plants have disappeared. In the present Clusius garden these have been temporarily replaced by new varieties that strongly resemble the old ones. In order to capture the atmosphere of a 15th-century garden as faithfully as possible, the climbing plant are guided along traditional sticks and pyramids and the trees are pruned in various shapes.

Also the pavilion, the symbolic center of the garden, has been painstakingly reconstructed. Several non-authentic aspects have been maintained out of practical considerations, notably the shell-paths and the brick borders of the beds.


Why has the Hortus Clusianus, the original Hortus from 1594, been reconstructed? The answer was given by Prof. Baas Becking and Mr. Veendorp in their history of the Hortus from 1938: 'The Hortus Clusianus was not only reconstructed out of nostalgia, but also because nearly every plant from the inventory of Cluyt is described in the books of Clusius; a reconstruction can lead to an understanding of Clusius' work.

'For the botanist the garden is a reminder that his field of science, just as our old Laburnum, has experienced a long development. For the chemist it gives an indication of the enormous knowledge of medicinal plants that Cluyt possessed and for the historian it is a living image of the birth of a branch of science.'

From dr. L.A. Tjon Sie Fat, De Tuin van Clusius: Het Ontstaan van de Leidse Hortus. Leiden, Hortus botanicus, 1992.



Clusiustuin, Hortus botanicus, Leiden

Home