Leo Lesquereux

Image source: Smithsonian Institution Archives

Andy Schmidt

History of Geology--GO 521
Dec. 2003


Leo Lesquereux , a bryologist and pioneering paleobotinist of the American coal measures, was born in Fleuier, Switzerland on November 18, 1806. As one of the founders of fossil botany in North America, his life story is perhaps one of the most remarkable yet tragic in the history of science (Andrews,1980). At an early age he exhibited a love of nature which took him on adventurous excursions into the nearby Juru Mountains where he would collect flowers, hazelnuts, and wild fruits for his mother (Lang, 1994). However, it was a near-fatal fall from the top of a cliff at the age of seven that left him bruised, lacerated, and unconscious. A lasting effect of the fall was a progressive loss of hearing which would have considerable ramifications in his professional life. Although he endured a traumatic event he resumed his passion for the outdoors undeterred continuing to explore the countryside particularly the peat bogs

After completing courses at the academy of Neuchatel in 1827, Lesquereux would travel to Eisenach, Saxony, earning his way tutoring French. He would marry one of his students, Sophie von Wolffskel von Reichenberg, the daughter of an honored general. Retuning to Switzerland he accepted a position as a teacher and later principal at the high school in Locle, but within three years his hearing had become so poor that he was forced to give up teaching and return to menial employment in his father’s watch factory. This was a difficult time for Lesquereux, deafness had driven him from his profession and society. It is during these difficult years that he would rekindle his interest in natural history. His spare time would be devoted to the unique flora that lined the high Jura valleys, particularly the Sphagnum and other rare mosses. Even without a formal education in botany he would still garner a reputation in bryology, leading scientists on collecting expeditions for rare mosses in the Jura Mountains.

European Peat Bogs

This region of Europe is noted for its ancient bogs that have been evolving over tens of thousands of years. It is here in the peat bogs of the Jura Mountains that Lesqueruex would find his life-long calling. In 1844 the Swiss government sponsored a contest for the best essay on the origin and use of peat with hopes of improving the nation’s fuel supply. Lesquereux would devise a special augur for collecting peat and he began research on its origin, composition, and development. This pioneering study would reveal the structure and character of peat deposits: its stratification, the specific gravity of its different layers, the deformation of Sphagnum by pressure, and rates of growth and decay. Lesquereux’s essay was awarded a gold medal, his authoritative work would be the first to determine the true causes and conditions of peat formation. J. Peter Lesley, a close friend and geologist, stated that he unconsciously made “the first step in the science of the geology of coal.”(Lesley,1895)

As a result of his peat studies he formed a close friendship with Louis Agassiz, who held the Chair of Natural History in the Academy of Neuchatel. He was also commissioned by the King of Prussia to explore and report on the peat bogs of Germany, Sweden, Denmark, Holland and France. During these travels he would become acquainted with numerous scientists and their fossil collections. His first encounter with fossil plant specimens from coal measures would occur at the Museum of Strassburg. In a letter to J.P. Lesley, Lesquereux reminisces:

“I felt as if I had been transported into another world, and could scarcely leave the large room where the specimens were exposed. I said to Schimper how happy a man should be with such an admirable vegetation to study! I did not dare ask him for even a small piece of one specimen, although I should have prized the smallest as a treasure. Was it a remembrance of some former life, or a prevision of what was to come to me in the hereafter?” (Lesley, 1895).

Move to America- Major Works

Due to political change sweeping through Europe in the late 1840’s, Lesquereux decided to move to America with his wife and five children. Arriving in Boston in 1847, he was offered a short-term job by his friend Agassiz. The job consisted of classifying plants that Agassiz collected in his Lake Superior expedition. After completing the report in 1848, Lesqueruex was desperately seeking work in a position of science. He believed the difficulty arose from people’s fear of his deafness. However, due to his reputation as an exceptional European bryologist , William S. Sullivant, America’s leading bryologist, invited him to Columbus, Ohio to assist him in his studies of mosses. Both worked side by side with mutual respect. Together they published two editions of Musci Exsiccati Americani (1856, 1865). In addition they published “Manual of the Mosses of North America” in 1885.

Lesquereux’s most influential research would take place in the field of paleobotany, the study of fossil plants. Upon reading a reference from Brongniart, a French paleobotanist, that coal-seams may have originated under conditions similar to peat bogs, Lesquereux began to develop theories on the origin of coal formations based on his knowledge of European peat bogs (Orton, 1890). In a report on the vegetable origin of coal in the 2nd Geological Survey of Pennsylvania, Lesquereux states that:

"The definition of a bed of peat is the same as that of a bed of coal. It is an accumulation of the remains of plants grown in situ, deposited each year, or after the cycle of their vegetation is completed, and superimposed without interruption, one layer upon another, until the accumulation becomes sometimes of great thickness, and covering a wide surface of land.”

His ideas on coal formation in relation to peat would introduce Lesquereux to America’s coal flora assemblages. Consulting for state geological surveys in Arkansas and Kentucky (for D.D. Owen), Illinois, Ohio, Indiana (for E.T. Cox), Minnesota (N.H. Winchell), and Pennsylvania ( for J.P. Lesley), Lesquereux contributed pioneering reports on Paleozoic floras through intricate illustrations and descriptions. Lesley’s first encounter with Lesquereux in Schuylkill, Pennsylvania:

“At this time I became acquainted with Lesquereux, as he sat day after day on the anthracite coal-tips turning over each piece of waste slate in search of plant impressions. His patient zeal was a wonder to my impatient and restless nature. The broiling sunshine, the chilly wind, the soaking rain were alike disregarded by him. The evening brought him no repose, for his bag of specimens was exhibited, re-examined, discussed, and sometimes figured then” (Lesley, 1895)

Out of all of his paleobotanical contributions to America’s state surveys, it is his comprehensive investigation of the rich Carboniferous flora of Pennsylvania that he is most remembered for. In 1958 he prepared “Catalogue of the Fossil Plants which have been named or described from the Coal Measures of North America” for the first Pennsylvania Geological Survey under H.D. Rogers. This was followed by his 1884 monumental work “Description of the Coal Flora of the Carboniferous Formation inPennsylvania and the United States” which included three volumes of text and an eighty-five plate atlas. Both of these works became the standard for carboniferous plants in the United States. In all, he published over fifty works and was a member of twenty scientific societies including the National Academy of Sciences.

Historical Context

Making significant contributions to the fledgeling state surveys and setting the standard for American paleobotanical research, Lesquereux is now recognized and honored throughout the scientific community. Without a college education and overcoming a significant handicap, he was able to persevere, due to his childhood fascination with the natural world and the support of a loving family. Although his disability could be considered and obstacle to many, it appears that Lesquereux may have appreciated the isolation brought on by his deafness. In an interview with L.R. McCabe he remarks:

“My associations have been almost entirely of a scientific nature. My deafness cut me off from everything that lay outside of science. I have lived with Nature, the rocks, the trees, the flowers. They know me, I know them. All outside are dead to me” (Lang, 1994).

Lesquereux lived a long and productive life, passing away on October 25,1889 at the age of 83. Through hardwork, patience, and a fixed pupose, Leo is an inspiration to all who may have to overcome obstacles.

Related Websites

  • Pennsylvania Fern Fossils--Neuropteris Ferns.


    Andrews, H.N. 1980. The fossil hunters: In search of ancient plants. Ithaca, NY: Cornell University Press.

    Lang, H.G. 1994. Silence of the spheres: The deaf experience in the history of science. Westprot, CT: Bergin and Garvey.

    Leo Lesquereux Biography, World Wide Web homepage. URL: http://faculty.evansville.edu/ck6/bstud/lesq.html

    Lesley, J.P. 1895. Memoir of Leo Lesquereux. National Academy of Sciences biographical Memoirs (Vol. 3, pp. 189-212). Washington, DC: National Academy of Sciences.

    Orton, E. 1890. Leo Lesquereux. American Geologist, 5, 284-296.