Tulipomania

by Mike Dash

  Clusius benefited as much as anyone from this sudden influx of confidence and funds. His principal task was to establish a hortus academicus at Leiden, in imitation of the one set up at the University of Pisa in 1543, which had been the first botanical garden in Europe. Since then similar gardens had been established at the universities of Padua, Bologna, Florence, and Leipzig, but there was still none in the United Provinces. Leiden’s hortus was thus an important symbol not just for the university but for all the Dutch Republic, and the garden was amply funded and laid out on a generous scale. When it was complete, it covered nearly a third of an acre and was divided into four main sections, each of which contained some 350 individual beds.

  With the memory of his frustrating years in Vienna still fresh, Clusius was particularly pleased with the rapidity with which his hortus was laid out and planted. He himself was by now too infirm to do any of the physical labor involved, but the university provided him with a very able assistant in the shape of an apothecary from Delft named Dirck Cluyt. Under Cluyt’s direction work on the garden was complete by September 1594, less than a year after Clusius’s arrival at Leiden. It made a pleasant contrast to the dilatoriness of Maximilian and the imperial court.

  The speed with which the hortus took shape helped to distract Clusius from some of the difficulties of living in Holland. He had to endure the hard winter of 1593–94, during which Leiden’s mice made short work of 150 of the precious bulbs in his personal collection, and then the miserable weather that the Low Countries experienced in 1594—a year of seemingly constant wind and rain that damaged many of the plants in the botanical garden and did nothing to improve the health of a man who was now sixty-eight years old.

  Although he was contractually obliged to look after the garden and to visit it each afternoon in summer to answer the questions of students and distinguished visitors, Clusius’s characteristic intractability led him to refuse his new employer’s request that he deliver lectures on botany as well. Instead, he devoted much of his time to beekeeping and to pottering about the private garden he had insisted that the curators provide for him. While the hortus was largely given over to herbs, medicinal plants, and exotic novelties such as the potato—only recently introduced from the New World and still regarded as quite possibly poisonous—Clusius sowed the collection of tulip bulbs he had brought with him from Frankfurt in his own garden, where he continued to cultivate the flower and delve into its mysteries until his death in 1609, at the very advanced age of eighty-three.

  Carolus Clusius was without question the most important botanist of his day. He was a true scientist whose greatest works, such as his surveys of the plants of Austria and Spain, remained the standard texts on their subject for more than a century. He was also a pioneer in the most literal sense—the brief history of fungi that he published in 1601 was more or less the first thing that had ever been written on the subject. For the last quarter century of his life he served as a sort of living vade mecum for the botanists and flower lovers of Europe, keeping up a vast correspondence. This, and his particular interest in bulbous plants, ensured that the tulip spread far more rapidly through Europe than might otherwise have been the case. From this point of view he really was, in the words of another valued compliment—this one from the pen of Prince Emanuel of Portugal—“true monarch of the flowers.”

  Yet Clusius’s importance, during his final years at Leiden, lay not so much in the bulbs he brought to the university as in how he studied them once they were planted. The old botanist was not the first person to grow tulips in the United Provinces; according to one reliable chronicler, that honor belonged to an Amsterdam apothecary named Walich Ziwertsz.,* a Protestant fanatic who is remembered chiefly for his denunciation of the popular custom of celebrating the festival of St. Nicholas on December 25. Ziwertsz. is known to have cultivated tulips in his garden before 1573, when Clusius was still in Vienna. Nor was the master of the hortus even the first person to raise the flower in Leiden; his own friend Johan van Hoghelande had planted bulbs at the university before his arrival, having received a small stock from Joris Rye. He was, however, the only man in the United Provinces—perhaps in all Europe—who was perfectly qualified to describe and catalog and understand the flower.

  Clusius’s first discussion of tulips appeared in his description of Spanish plant life, the Historia of 1576. Over the years he amended and expanded this early work, publishing enlarged treatises on the flower in 1583 and finally in his masterpiece, the Rariorum Plantarum Historia, which appeared in 1601 while he was still at Leiden. It is largely thanks to these works that we know as much as we do about the early history of the tulip in Europe. Clusius’s treatises also included a detailed description of the flowers he had personally encountered or heard of from his many correspondents. In common with all contemporary botanists who took an interest in the genus, he was principally impressed by the ease with which new varieties of tulip could be produced. No other flower, he observed—except perhaps the poppy—was remotely as diverse.

  Thanks largely to the efforts of the gardeners of Istanbul, the number of tulip variants known in Europe—each distinguishable by its unique color scheme or the shape and arrangement of its leaves and petals—was already substantial in Clusius’s day. The botanist himself was able to catalog no fewer than thirty-four separate groups, which he classified according to their colors and their shape. He was also the first to distinguish between early-, mid-, and late-flowering tulips, of which the first appear in March and the last not until May.

  Working from the solid foundation that Clusius provided, later botanists have added considerably to our understanding of the tulip. The flower has now been grouped with other bulbous plants such as the iris, the crocus, and the hyacinth and is classified among the Liliaceae. In all about 120 different species of tulip—and countless individual varieties—have been cataloged to date.

  In scientific works an important dividing line is drawn between what are known as botanical tulips, which originate in the wild, and cultivars, which are hybrids reared in the garden. In Clusius’s time the tulips that were produced in the United Provinces were a mixture of wildflowers and an ever-increasing proportion of cultivars, the earliest of which were produced by chance crossings of two botanical tulips. Botanists have been able to identify fourteen different species of wildflowers as the building blocks that produced the flood of Dutch cultivars that adorned the seventeenth century. Not all played an equal part in creating this diversity. Some botanical tulips produce hybrids more readily than others, and the most malleable species that had found their way to the Dutch Republic included the Persian tulip—today known in Clusius’s honor as T. clusiana—the tapered tulip, T. schrenkii, and the fire tulip, T. praecox. Genes from these species were present in a large proportion of the cultivars that excited admiration in the Netherlands, but in truth Dutch tulips had been produced by crossing flowers that had come to the United Provinces from all points east, from Crete to Kurdistan. That was the secret of the tremendous variety they exhibited.

  Whether they were botanical species or cultivars, tulips could be grown from either seed or bulbs. Growing from seed is a chancy business; because plants grown from a single pinch of seed gathered from just one flower can exhibit considerable variation, it is impossible to know exactly what sort of tulip will emerge at the end of this time. Important details such as the color and the pattern of the flower can only be guessed at, which makes the process frustrating for anyone seeking consistency. And it takes six or seven years to produce a flowering bulb from seed, a very time-consuming process that must have seemed even more so in an age when the average life expectancy was not much more than forty years.

  Once a tulip grown from seed has matured and flowered, however, it can also reproduce itself by producing outgrowths known as offsets from its bulb. These are effectively clones of the mother bulb and will produce flowers that are identical to it. Offsets can be separated from the mother bulb by hand and, in another year o
r two, become bulbs capable of flowering themselves. From the point of view of both the commercial grower—who seeks consistency—and the gardener—who prefers not to wait seven years to see a flower—propagation through offsets is infinitely preferable to raising tulips from seed. However, reliance on outgrowths does have one significant disadvantage: Most tulip bulbs will produce only two or three offsets a year and can do so for only a couple of years before the mother bulb becomes exhausted and dies.

  For this reason new varieties of tulips multiply only very slowly at first. Once a grower has identified, in a single flower of some new variety, great beauty or strength that he may be able to sell, he will have—even if all goes well—quite possibly only two bulbs the next year, four the year after that, eight in the next year, and sixteen in the fourth year of cultivation. If he parts with some of these bulbs, moreover, he limits his own ability to produce large quantities of the new variety. Plainly, then, it can take a decade for a new tulip to become available in any sort of numbers—and in Golden Age Holland, where propagation was a poorly understood mystery at best, the number of bulbs that were actually produced would have fallen well short of the theoretical maximum. Any rare and coveted variety would thus inevitably remain in short supply for a number of years, and there was nothing that even the most brilliant bulb growers could do to increase production to meet demand.

  As soon as tulips of different species are placed close together in gardens, where insects can take pollen from one flower to another, the chance of producing hybrids is substantially increased. And as the new varieties thus created are themselves crossed with other flowers, increasingly elaborate cultivars emerge, bearing the different characteristics of their many forebears. Because tulips of different species do not often grow together naturally, complex hybrids of this sort do not easily occur in the wild. They are, in the strict sense of the word, freaks. But they are also less straightforward, subtler than wildflowers, and thus much sought after by connoisseurs.

  The most favored tulips were those that exhibited the most perfect petals and the most eye-catching markings. Indeed, Dutch cultivars of the Golden Age were celebrated and valued far beyond the borders of the republic for the elaborate and often riotous colors they exhibited. By the middle 1630s no fewer than thirteen groups of flowers had been created, each with its own distinctive color scheme. These ranged from the Couleren, which were simple, single-colored tulips in red or yellow or white, to the rare Marquetrinen—late-flowering varieties that exhibited at least four colors. The Couleren would have been botanical tulips, or at least cultivars closely related to them, while Marquetrinen tulips must have been fairly complex hybrids. The latter were grown mostly in Flanders and France and do not figure in the records of the tulip mania.

  In the Dutch Republic the most popular of the thirteen groups were the Rosen, the Violetten, and the Bizarden. Rosen varieties, which were by far the most numerous, were colored red or pink on a white ground. During the first third of the seventeenth century, almost four hundred Rosen tulips were created and named. The seventy or so Violetten, as their name suggests, were purple or lilac on white, and the Bizarden, which on the whole were the least favored of the three and existed in only two dozen varieties, were colored red, purple, or brown on yellow. Varieties that reversed the usual color schemes also existed and were generally classed with them; for example, Lacken tulips were purple flowers with a broad white border and were grouped with the Violetten, while the handful of Ducken cultivars, which were red with a yellow border, could be found among the Bizarden.

  It was the patterns that these contrasting colors formed that really excited gardeners, and it is impossible to comprehend the tulip mania without understanding just how different tulip cultivars were from every other flower known to horticulturists in the seventeenth century. The colors they exhibited were more intense and more concentrated that those of ordinary plants; mere red became bright scarlet, and dull purple a bewitching shade of almost-black. They were also brilliantly defined, quite unlike the indefinite flushing displayed by other multicolored flowers as their petals shaded gradually from one color to another.

  The distinguishing colors of Dutch tulip cultivars—the reds of Rosen tulips and the purples of the Violetten—generally appeared as feathers or flames that ran up the center of each petal and sometimes also formed a border around its edges. These colors occasionally also appeared as mottled patches on the plant’s stem, though they never tainted the purity of the flower’s base, which was always either white (sometimes tinged with blue) or yellow, depending upon the variety. The patterns were unique to each flower, and though two plants of the same variety might closely resemble each other, they were never absolutely identical.

  From the earliest days of the bulb craze, Dutch tulipophiles used the subtle variations of these flames and flares of color to grade their flowers according to a strict set of criteria. The most highly prized tulips, termed “superbly fine,” were broken varieties that were almost entirely white or yellow in color, displaying their flames of violet, red, or brown only in thin stripes that ran along the center and the edges of their petals. Flowers that in the opinion of the connoisseurs flaunted their bright colors too wantonly were termed “rude” and were much less cherished.

  Botanical tulips are noted for their robust and simple color schemes, so how did the celebrated cultivars of the Dutch Golden Age become so elaborately colored? The solution to this problem is simple but disturbing: They were diseased. The great irony of the tulip mania is that the most popular varieties, the ones that changed hands for hundreds or even thousands of guilders, were actually infected with a virus, one apparently unique to tulips. It was this virus that caused both the spectacular intensity and the variations in the colors of their petals and that explained why tulips, alone among the flowers of the garden, displayed the distinct, intense, and brilliant colors that collectors came to crave.

  Even in Clusius’s day it was obvious that something strange was happening to the tulips grown in Leiden and elsewhere. A bulb that one year had produced a unicolored tulip might become a Rosen or a Bizarden the next. This process was known as “breaking,” and the bulb of a flower that had undergone the process was said to be “broken” while those that remained unicolored were called “breeders.” The whole process was extremely unpredictable. There was no way of telling if or when a flower would break; one tulip might bloom in the spring with a dazzling new array of colors, while another, of the same variety and planted next to the first in the same flower bed, remained quite unaffected. Breaking was common in some years, less so in others. Similarly, a broken bulb might—albeit rarely—produce an offset that turned out to be a breeder, and no grower could be sure that a breeder bulb would not break. The only certainties seemed to be that tulips grown from seed were invariably breeders and that, once broken, a mother bulb would never again produce a unicolored flower.

  There were clues here to the nature of the disease, and Clusius was a careful enough observer to notice that broken tulips were slightly smaller and definitely weaker than the flowers produced by breeder bulbs. But at a time when the mechanisms by which diseases are communicated remained unguessed at, the phenomenon of breaking seemed akin to magic to most of his contemporaries. Try as they might, growers could not force a breeder bulb to break when they wanted it to. Some turned to alchemical potions made of pigeon dung, which they applied to the bulbs; others tried cutting the bulbs of two different-colored tulips in two and binding the opposing halves together in the hope of producing a flower sporting both colors. These devices rarely had the desired effect.

  Exactly when the tulip became infected with a virus is not certain. The earliest observations of the phenomenon date to about 1580, but the disease was probably older than that. In truth the plant became vulnerable to disease as soon as it entered a garden; any flowers raised in artificial proximity by humans face threats they do not encounter in the wild. Cultivars may be poorly cared for or discarded in favor of so
me new favorite, but in particular they can pick up diseases to which the more robust botanical species have developed an immunity or that at least spread more slowly in the wild.

  The mystery of breaking remained unsolved until well into the twentieth century, when the agent that causes the disease, sometimes called the mosaic virus, was finally identified by staff at the John Innes Horticultural Institution in London. By permitting aphids to feed on broken bulbs and then on breeders, they were able to show that the breeder bulbs visited by the aphids broke twice as often as a control sample—thus simultaneously proving that the disease was caused by a virus and demonstrating the mechanism whereby it was transmitted from one tulip to another. Further experimentation showed that the mosaic virus could infect both a flower when it was growing in a garden and a bulb that was being stored prior to planting. Perhaps ironically, given the efforts of old Dutch growers to induce breaking by binding half-bulbs together, the method used at the John Innes Institute to persuade aphids to feed alternately on infected and uninfected tulips was to graft halves of broken bulbs onto breeders.

  Well before Clusius’s death, the broken tulips he grew in his private garden at Leiden were attracting the attention of connoisseurs eager to secure specimens of these unique new flowers for their own gardens. The old botanist soon found himself almost overwhelmed with requests for tulip bulbs. Many, he knew, came from people who merely wanted to follow the fashion for the flower and had no real interest in botany and no idea how to cultivate bulbs; others were from people he suspected of planning to sell his bulbs for whatever they could get. In any case, his own supplies were not remotely adequate to meet the demand. “So many ask for them,” he wrote to his friend Justus Lipsius, a humanist scholar who had been one of the pillars of Leiden University in its formative years, “that if I were to satisfy every demand, I would be completely robbed of my treasures, and others would be rich.”