(b. Calw, Germany, 12 March 1732; d. Calw, 14 June 1791)
While Gaertner is best known for his De fructibus et seminibus plantarum (1788–1792), which describes the fruits and seeds of 1,050 genera, Julius von Sachs considered his “valuable reflections” on sexuality in plants to be of great theoretical significance.
Gaertner was the son of a court physician. Orphaned at a young age, he was first destined for the church, then law, and finally medicine. In 1751 he entered the University of Tübingen, where he came under the influence of Haller. He received the M. D. degree from Tübingen in 1753 with his dissertation “De viis urinae ordinariis et extraordinariis,” but he did not practice medicine. After visiting several cities in Italy, he arrived in Lyons, then spent six months each in Montpellier and Paris, and tarried in England for nearly a year (1755), pursuing mathematics, optics, and mechanics. During 1759 he attended with enthusiasm Adrian van Royen’s botany lectures at Leiden and he soon commenced marine investigations. Peter Pallas published Gaertner’s studies on zoophytes, and his “Account of the Urtica marina in a Letter to Mr. Peter Collinson” appeared in the Philosophical Transactions of the Royal Society, 52 (1761), 75–85.
Gaertner became in turn professor of anatomy at Tübingen, professor of botany at St. Petersburg, cataloger of the empress’ cabinet of curiosities, and botanical traveler with Count Grigory Orlov in the Ukraine, where he discovered many underscribed plants before returning to Calw in 1770. Thenceforth he gave his attention to carpology.
Learning that Sir Joseph Banks, Daniel Solander, and the Forsters had brought back rich collections of plants and seeds from Cook’s voyages around the world, Gaertner hastened to England in the spring of 1778, seeking to add these novelties to his survey of fruits and seeds. He found Banks openhanded in granting their study and in gifts of duplicates for use in De fructibus. At Rotterdam, Gaertner met Karl Thunberg, who, recently returned from South Africa and Japan, also generously assisted him. From these collections, as well as those found in botanical gardens at Leiden, Amsterdam, and Lyons, and pharmaceutical plots at Stuttgart, Gaertner proposed fifty new genera.
De fructibus was issued in five parts, the first late in 1788 (cf. Frans Stafleu, “Dates of Botanical Publications, 1788–1792” , and Taxonomic Literature ). The Supplementum carpologicae, issued in three parts (1805–1807), was published in Leipzig by Gaertner’s son, Karl Friedrich. Volume I of De fructibus was fittingly dedicated to Banks and illustrated from Gaertner’s sketches with 180 copperplate drawings by Gaertner and by Hermann Jakob Tyroff. The work, however, went almost unnoticed in Germany where only 200 copies were sold in three years, and this commercial failure even threatened its completion. Yet in France, it met with appreciation, coming as it did at the same time as Jussieu’s Genera plantarum (Paris, 1789).
Gaertner demonstrated that the spores of Cryptogamia (which he called gemmae), being without an embryo yet capable of germination, were essentially different from seeds of Phanerogamia, which contain an embryo. He recognized that the early stages of an organ presented more significant information on origins and affinities of different forms than did a comparison of their mature condition. He established terminology, heretofore vague, for fruits and seeds. He distinguished between the pericarp, however dry and anomalous it may be in one-seeded fruits, and integuments. Further, he characterized endosperm (calling it albumen) as distinct from cotyledons, which he correctly interpreted as appendages of the embryo. His scheme of classifying fruits and seeds contributed importantly to Jussieu’s emerging natural system of plant families.
The Achilles’ heel of Gaertner’s interpretation was his concept of what he called the vitellus, a term he used to embrace such diverse structures as the scutellum of grasses, cotyledons of Zamia, and the spore contents of various Cryptogamia. In the course of examining the reproductive structures of Spirogyra, Gaertner witnessed zygospore formation. This observation led Johann Hedwig to suggest, and Jean Vaucher subsequently to assert, that true sexuality occurs in algae.
I. Original Works. For bibliographic details of De fructibus see Frans Stafleu, “Dates of Botanical Publications, 1788–1792,” in Taxon,′12 (1963), 60–62, and Taxonomic Literature (1967), 162–163. Gaertner’s minor papers are listed in Jonas Dryander, Catalogus bibliothecae historico-naturalis Josephi Banks (London, 1798–1800).
II. Secondary Literature. For interpretative commentary on Gaertner, see Julius von Sachs, Geschichte der Botanik vom 16. Jahrhundert bis 1860 (Munich, 1875), 132–135, 222, 447; English trans. by H. E. F. Garnsey and Isaac Bayley Balfour (Oxford, 1906), 122–125, 207, 413; French trans. by Henry de Varigny (Paris, 1892), 128–132, 216–428.
The fundamental biographical account is Joseph P. F. Deleuze, “Notice sur la vie et les ouvrages de Gaertner,” in Annales du muséum national d’histoire naturelle, 1 (an XI ), 207–233, to which a few details are added by François Chaumeton, in Biographie universelle, XV (1856), 342–343; and Paul Ascherson, in Allgemeine deutsche Biographie, VIII (1878), 377–380. A calendar of eight letters from Gaertner is given by Warren R. Dawson, The Banks Letters (London, 1958), 351–352. Stafleu (cited above) presents different evidence from George K. Brizicky, “Dates of Publication of Gaertner’s De Fructibus et Seminibus Plantarum,” in Rhodora, 62 (1960), 81–84.