Foreword to Duchesne's gourds drawings

Text published in : Paris, Harry S., 2007. The drawings of Antoine Nicolas Duchesne for his Natural History of the Gourds / Les dessins d'Antoine Nicolas Duchesne pour son histoire naturelle des courges. Paris, Publications scientifiques du Muséum national d'histoire naturelle. (coll. Des Planches et des Mots 4). 454 p.

Antoine Nicolas Duchesne is mostly known for his Histoire naturelle des fraisiers (Natural History of Strawberries, 1766). At the time of publication of his strawberry drawings in this collection (Staudt, 2003), I was stressed by the fact that Duchesne's ideas were those of a forerunner; he was indeed conscious of this status when qualifying himself as a 'cultivator botanist', and thus distinct from 'deep naturalists'.

With this work about cucurbits initiated immediately after strawberries, we can but admire Duchesne for being so constant-minded and incredibly ambitious in attempting to put some order in a plant group whose diversity of forms and colors defies understanding still today. Accomplishing this task needed an unfailing tenaciousness and a deep sense of observation. In his commentaries, Paris expresses how much Duchesne was right, in quite all the cases.

The publication of Duchesne's cucurbit drawings represents a considerable event for the history of crops. With 258 color plates figuring about a hundred cultivars, this book offers us an exhaustive panorama of the range of cultivars known in Europe at the end of the 18th century, that is less than three centuries after 1492, starting point of a long period of plant exchanges between the Old and the New World.

With Duchesne' work on strawberries, we could assist to the birth of a new species of strawberry under domestication. But with the work on cucurbits, the emphasis shifts to the birth and diversification of cultivar-groups within one species, Cucurbita pepo L. We now know for sure that all Cucurbita species originate in the New World, and arrived into Europe after 1492. Those introductions have probably spread over a long period, along with the progress of European colonisation in all the regions of the New World. Thanks to the writings of Paris, we can have a good idea of the cultivar-groups which had already differentiated, and of those which had still not appeared. The plant historian will remind above all the fact that most of the Cucurbita grown in Europe were first ornamental forms without a culinary interest, that is gourds. He will also take note that several centuries were needed before the introduced germplasm could evolve and adapt to new environmental conditions, in particular the long days of temperate climates, whereas many tropical Cucurbita were short-day plants. And yet the biology of Cucurbita was suitable for a quick evolution, as they were preferentially cross-breeding (allowing character recombination at each generation) as well as self-compatible (allowing the fixation of cultivars through self-pollination, be it natural or artificial when the gardener does it himself). Moreover, we can estimate that many gardeners have soon been attracted by such curious and showy plants, and that seed exchanges through Europe and with what was to become the United States were heavy, which favored hybridizations.

Historians, anthropologists and agronomists will still have to understand more in detail the dynamics of creation and dissemination of the diverse cultivar-groups, and to appreciate the relative weight of biological, technical and cultural factors in this history. This difficult and ambitious task still remains at a draft stage. Crop historians, following Alphonse de Candolle (1882), have made efforts in tracing the origin of species, their introduction into different countries and their history. This task has not come to an end, but it suffers from the fact that it sticks to the species level. However, we know that within one and the same biological species, cultivars and cultivar-groups may coexist with very different forms, biology and above all use characteristics. And each of these cultivar-groups may have it own history.

This task is difficult, because it supposes that a considerable corpus of data is available. The first condition is the availability of an exhaustive referential of the botanical and genetic diversity of the plant complexes involved. This referential now exists for Cucurbita pepo L., and more generally for the Cucurbita genus. It is required because a plant can be identified (particularly in historical sources) only if it has previously been noticed and adequately described, and if this description has been made available to scientists of other disciplines. But a botanical description is not enough. It must integrate data of technological interest, such as dry matter content of the pulp, chemical composition, characteristics of the fruit rind or the seed testa, in general everything which makes possible a particular use. Uses actually determine the fate of a particular plant form and its perception by people.

The second condition is the availability of a complete inventory of popular names in many languages. Such an inventory is particularly critical in the case of Cucurbitaceae, which present so many similarities through botanical species and genera, a fact that Vavilov has formalized under his 'law of parallel variations'. Those similarities do explain why newly introduced plants have often been given the same popular names as the plants previously known. This process is well known by linguists, and has occurred in all the languages and dialects at all times, in such an extent that it can be asserted that all the identifications made by historians (not speaking of lazy authors of popular books) need to be checked. This is all the more important given that, as we go back in history, descriptions become terse and are reduced to the simple mention of a name, and anachronism is ready to spring up. Besides those processes of name changes, we have to deal with the variation of popular taxonomies between languages. This proved a formidable problem when elaborating this bilingual book. A 'gourd' in English is not necessarily a 'gourde' in French, and the distinction between 'squash' and 'pumpkin' doesn't match with the one between 'courge', 'citrouille' and 'potiron'.

Another corpus of data, very well used by Paris in his research work on the history of gourds, is iconography. The interest of iconography has been convincingly demonstrated by Banga (1957) for the history of carrots, as the Dutch still life paintings allow us to precisely date the appearance of orange carrots during the 18th century. Similarly, Finan (1948) could show that two different types of maize were known in Europe at the Renaissance, which is interpreted now as the trace of two distinct introductions, one of a tropical maize from the Caribbean, and the other of a temperate maize from Northern America, this last introduction not being documented by historians. But the use of iconography has remained limited due to technical (cost of reproductions) and legal or financial constraints (copyright of musea and libraries on the works they keep, and copyright of photographers). With the spread of Internet, we can but hope that solutions be found that allow iconography to be made fully accessible. In order to be useful, a vast corpus will be necessary, and not simply isolated images. On the other hand, a context of collaborative work will have to be created, allowing cross-approaches of specialists from diverse disciplines. Experience tells us that art historians are not prepared to observe the characters that are of interest for agronomists or geneticists, and at the reverse, the latter often lack historical knowledge.

While waiting for such desirable developments, all the cucurbit specialists and amateurs will not deny themselves the pleasure of consulting this book which will be ranked as a landmark in the field of compared cucurbitology! Nobody better than Harry Paris was highly qualified to describe and interpret Duchesne's drawings, combining his deep knowledge of gourds with his tenaciousness in solving the bibliographical mysteries surrounding such an unrecognized work.

• Banga O., 1957. The development of the original European carrot material. Euphytica, 6 : 64-76.
• Candolle Alphonse de, 1882. L'origine des plantes cultivées. éd. 1. Paris, Germer Baillière, 1883 [en fait, 1882]. VIII-379 p.
• Finan John J., 1948. Maize in the great Herbals. Ann. Missouri Bot. Gard., 35 : 149-183.
• Staudt, Günter, 2003. Les dessins d'Antoine Nicolas Duchesne pour son Histoire naturelle des fraisiers. Préface de Michel Chauvet, pp. 9-15. Paris, Muséum national d'histoire naturelle. 370 p. (Collection "Des planches et des mots").
• Zeven A.C. and W.A. Brandenburg. 1986. Use of paintings from the 16th to 19th centuries to study the history of domesticated plants. Econ. Bot., 40: 397–408.