SESSé Y LACASTA, MARTíN DE

(b. Baraguas, Aragón, Spain, 11 December 1751 [?]; d. Madrid, Spain, 4 October 1808)

botany.

Sessé studied medicine, practiced in Madrid (1775–1776), then served as an army doctor in Spain and in Cuba. He moved to Mexico City in 1785. On 13 March 1787 he was named director of the Royal Botanical Expedition to New Spain and director of the Royal Botanical Garden in Mexico City. Early in 1789 Sessé gave up his medical work to devote full time to botany. He continued to hold his two directorships until he returned to Spain. In spite of the pressure of administrative detail involving the expedition and the garden, he took part in long field excursions to western Mexico (1789–1792), to the Atlantic slope of Mexico (1793), and to Cuba and Puerto Rico (1795–1798). Sessé left Mexico for the last time about April 1803 and reached Spain in November, having stopped in Cuba to arrange for the shipment of his West Indian collection, the bulk of which reached Madrid in June 1804. He seems to have accomplished little in his remaining years.

Sessé was a competent botanist, as is shown by his existing manuscript notes and botanical descriptions. He apparetly enjoyed collecting and analyzing plants in the field and understood thoroughly the standard practices and concepts of his day. Sessé’s contribution to botany is linked with that of José Mariano Mociño and can hardly be considered apart from it. The posthumous works Plantae Novae Hispaniae and Flora Mexicana were attributed to Sessé and Mociñ as joint authors, but it is probable that a major part of the botanical study and writing was done by Mociño under the nominal direction of Sessé, whose principal contribution to science seems to have been related to his administrative and executive functions.

It was Sessé who originally conceived and proposed the Botanical Expedition to New Spain, and with Vicente Cervantes he helped plan and maintain the Botanical Garden in Mexico. He dealt with several viceroys in turn, keeping them informed of progress and trying to convince them of the continuing value of the botanical work. Under his direction the members of the expedition conducted or took part in major excursions to all parts of Mexico except the extreme north, to Central America as far as Costa Rica, to the Greater Antilles, and to the northern Pacific. For about fifteen years he kept a group of temperamental naturalists and artists occupied and relatively contented (with the conspicuous exception of Longinos Martínez), sometimes under very trying circumstances. Finally, he managed to return to Spain with all the expedition’s collections, manuscripts, and paintings intact.

BIBLIOGRAPHY

I. Original Works. Two volumes, attributed to sessé and Mociño jointly, were published in Mexico between 1887 and 1897. These appeared first in parts, as supplements to the periodical La Naturaleza. Plantae Novae Hispaniae (1887 – 1891) was based on a MS written by Mociño, completed at Guadalajara, Jalisco, forwarded from there to the viceroy, the Conde de Revilla-Gigedo, in July 1791, and now in the archives of the Instituto Botánico “A. J. Cavanilles,” Madrid. It is a complete flora, including the species of flowering plants studied by the Botanical Expedition up to about the beginning of 1791. A 2nd ed. was published in book form at Mexico City in 1893.

Flora Mexicana (1891 – 1897) was based on a very heterogeneous series of notes on individual plant-species, from many parts of Spanish America. These comprised a part, but by no means all, of the notes prepared by the members of the Botanical Expedition. Discovered, in no particular order, in the archives at Madrid, the notes were organized by the editor into the Linnaean classes and were published without careful study or collation. A 2nd ed. was published in book form at Mexico City in 1894, before the later parts of the first edition appeared in Naturaleza.

Original letters, memoranda, and other documents relative to the Botanical Expedition to New Spain are to be found in the Mexican National Archives, sec. “Historia,” vols. 460 – 466, 527. A few documents apparently of similar origin are in the William L. Clements Library, University of Michigan, Ann Arbor. Sessé’s official correspondence as director of the Expedition and of the Royal Botanical Garden is voluminous. The papers of Revilla-Gigedo, acquired in 1954 by a private collector in the United States, contain some information not accessible elsewhere but have been little studied in this connection.

The richest source of MS material in Spain is the archive of the Instituto Botánico “A. J. Cavanilles,” Madrid. It contains most of the existing MSS dealing with strictly botanical matters of the expedition to New Spain: the MS of Plantae Novae Hispaniae, various botanical descriptions, fragments of unpublished floras (including a “Flora guatemalensis” by Mociño), inventories of paintings, and collections from the various excursions carried out in Mexico. Descriptions or copies of most of these inventories have been published by Arias Divito (see below) or in the papers cited by him. Arias Divito also lists (p. 307) the other major sources of MS material in Madrid and Seville.

II. Secondary Literature. An extensively documented account of Sessé, and their co-workers, based primarily upon materials in the Archivo General de la Nación, Mexico City, is H. W. Rickett, “The Royal Botanical Expedition to New Spain,” in Chronica botanica, 11 (1947), 1 – 86. Juan Carlos Arias Divito, Las expediciones científicas españolas durante el siglo XVIII (Madrid, 1968), is based primarily on Spanish archival sources. It includes copies of many previously unpublished inventories of plants, animals, and paintings, and a considerable bibliography that supplements the references cited by Rickett. Additional information especially, relative to the members of the Malaspina Expedition who were in Mexico at the same time as the Royal Botanical Expedition, is in Iris Higbie Wilson, “Scientific Aspects of Spanish Exploration in New Spain During the Late Eighteenth Century” (Ph.D. diss., Univ. of Southern California, 1962).

The story of the disaffected naturalist Longinos Martínez, who left the Botanical Expedition after a long and bitter quarrel with Sessé, is told in Lesley Bird Simpson, Journal of José Longinos Martínez (San Francisco, 1961).

The botanical specimens collected in New Spain from about 1787 to 1799 number more than 10,000; perhaps 8,000 compose the “Sessé and Mociño” herbarium at the Instituto Bot´nico “A. J. Cavanilles,” Madrid; and several thousand duplicates are scattered through the larger European herbaria, especially those in London, Paris, Geneva, Florence, and Oxford. After the death of Sessé and the flight of Mociño with the retreating French in 1812, the Spanish botanist José Antonio Pavó sold to collectors at least 15,000 duplicate specimens, including many of those collected by the expedition of Sessé and Mocinño. As these found their way gradually into large public and private herbaria, they were much studies and cited by botanists, and thus ironically became of more scientific value than the original herbarium, which remained unstudied in Madrid. Much effort has been expended in recent years, as more has become known of the work of the Botanical Expedition, in documenting these specimens that constitute perhaps the most valuable part of the legacy of Sessé and Mociño. A part of the story of their sale and the dispersal of duplicate specimens from New Spain is told by Arthur Robert Steele in Flowers for the king (Durham, N.C., 1964), 291–315, which describes in detail Pavón’s dealings with Aylmer Bourke Lambert and Philip Barker Webb. An uncataloged MS in the department of botany, British Museum (Natural History), lists the plants sold by Pavón to Lambert and later bought for the Museum.

Rogers McVaugh