(b. Fleurier, Neuchâtel, Switzerland, 18 November 1806; d. Columbus, Ohio, 25 October 1889),
The earliest authority in the United States on fossil plants and its second-ranking bryologist, Lesquereux was an expatriate from the political revolution of 1847-1848, as were Louis Agassiz and Arnold Guyot. Lesquereux was of French Huguenot ancestry, the only son of V. Aimé and Marie Anne Lesquereux. His father was an unlettered manufacturer of watch springs. His well-read mother wished him to become a Lutheran minister. At the age of ten he suffered a near-fatal fall that brought on partial deafness. After two years at the Collège of Neuchâtel, where he was a classmate of Guyot, he taught French at Eisenach with the intention of entering a university later. In 1830 he married Sophia von Wolffskel von Reichenberg, daughter of a general attached to the court of Saxe-Weimar; they had four sons and a daughter. Lesquereux discontinued his teaching because of his growing deafness and returned to Neuchâtel and the engraving of watchcases. It was probably while convalescing from a prolonged illness there that he became interested in mosses. He told Henry Bolander that he owed his enthusiasm for mosses to Wilhelm Schimper, whom he called facile princeps bryologorum. In an effort to enhance to nation’s fuel supply the Swiss government offered a prize for an essay on the formation of peat bogs, and Lesquereux won. His essay, on the peat bogs of the Jura (1844), attracted the notice of Louis Agassiz, who was then at Neuchâtel.
Discouraged by the political ferment of the times and encouraged by Agassiz, Lesquereux and his family took steerage passage for Boston, arriving in September 1848. Agassiz at once employed him in classifying plants that he had collected on his 1848 expedition to Lake Superior. W. S. Sullivant, the country’s leading bryologist and a well-to-do businessman of Columbus, Ohio, urged Lesquereux to work with him in the preparation of Musci boreali-americani (1856; 2nd ed., 1865) and Icones muscorum (1864). Lesquereux supplemented his income by a small jewelry business. In 1849 he toured the southern states for Sullivant and began writing a series of twenty-seven “Lettres écrites d’Amérique destinées aux émigrants,” articles rich in commentary on American mores that were published in Neuchâtel’s Revue suisse. Sullivant and Lesquereux began a Manual of the Mosses of North America, but it was interrupted by Sullivant’s death in 1873 and by Lesquereux’s failing eyesight. Lesquereux then enlisted Thomas Potts James to assist with the microscopic examinations; and the 447-page Manual, describing about 900 species, was published under their authorship (Boston, 1884) two years after James’s death. Lesquereux’s later years were spent naming fossils.
His first paleobotanical publication was a monograph of Carboniferous fossils of Pennsylvania (1854), followed by another on Illinois (1863), from which the locality of Mazon Creek became a classic. From 1867 to 1872 he organized the fossils that had accumulated at Harvard’s Museum of Comparative Zoology; this was his only institutional affiliation. This engagement contributed to his monumental three-volume Coal Flora of Pennsylvania (1879-1884). Later R. D. Lacoe of Pittston, Pennsylvania, engaged Lesquereux as a semipensioner to organize his large private collection of fossils, which he bequeathed to the National Museum (now the National Museum of Natural History) in Washington, D.C.
I. Original Works. No thoroughly satisfactory bibliography of Lesquereux’s publications has appeared; imperfect but useful are those by McCabe and Smith, cited below, and John M. Nickles, “Geologic Literature on North America, 1785-1918,” in Bulletin of the United States Geological Survey, no. 746 (1923), 654-656. The essay that attracted Agassiz was published as part of “Quelques recherches sur les marais tourbeux en général,” in Neuchâtel Société des Sciences Naturelles, Mémoires,3 (1844), 1-138. Lettres écrites d’Amérique (Neuchâtel, 1849) was published in an enlarged ed. (Neuchâtel, 1853). The Lesquereux-James correspondence (1857-1881) of 270 letters, bound in 3 vols., is at Farlow Cryptogamic Laboratory, Harvard University; and 58 letters (1862-1872) to Henry Nicholas Bolander are at the Bancroft Library, Berkeley, California. An autobiographical letter was published as a pref. to Lesquereux’s posthumous “Flora of the Dakota Group,” in Monographs of the U.S. Geological Survey,17 (1892), 1-400, reprinted in lsis, 34 (1942), 97-98. There is no catalog of his type specimens, figures, or cited specimens (2,460 in all), but according to W. C. Darrah, quoted in Sarton (see below), 1,415 specimens having the “status of types” are at the Botanical Museum, Harvard. His flowering plants, preserved in the British Museum (Natural History) and elsewhere, are numbered for example “Lx. 121” but lack date of collecting.
II. Secondary Literature. Some authors give Charles as his first name, but he never used it in his letters or writings, as noted by G. P. Merrill, in Dictionary of American Biography XI (New York, 1933), 188-189. J. Peter Lesley, who met Lesquereux in 1851, wrote the most detailed account of his earlier life, in Biographical Memoirs. National Academy of Sciences,3 (1895), 187-212, although the date of Lesquereux’s death given there, 20 Oct., is an error. Heretofore unpublished facts regarding his parents, portraits, collections, and published facts regarding his parents, portraits, collections, and publications are presented with charm by George Sarton, in Isis,34 (1942), 97-108; but Sarton’s fig. 6 of a page of “MS preface to Manual of Mosses” is in the hand of Asa Gray and not of Lesquereux. Sereno Watson’s handwriting appears on p. 18 ff. Both Gray and Watson edited the Manual MS. According to Charles R. Barnes, in Botanical Gazette,15 (1890), 16-19, mementos of Lesquereux were presented to the Musée d’Histoire Naturelle at Neuchâtel. The sketch by Annie M. Smith, in Bryologist,12 (1909), 75-78, includes a portrait; as does that of L. R. McCabe, in Popular Science Monthly,30 (1887), 835-840, which is based on an interview with Lesquereux. Charles H. Sternberg, Life of a Fossil Hunter (New York, 1909), pp. 21-25, published Lesquereux’s letter of 14 Apr. 1875 in facs. Additional biographical notes will be found in W. C. Darrah, “Leo Lesquereux,” in Harvard University Botanical Museum Leaflets, 2(1934), 113-119; and in Andrew Denny Rodgers, III, Noble Fellow, William Starling Sullivant (New York, 1940), pp. 191-204, and passim.