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Pennsylvania Roots of American Plant Knowledge

This article outlines the contributions of John Bartram, William Bartram, and Henry Muhlenberg to botanical knowledge during the years leading up to the American Revolution and in the new republic.

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June 24, 2026

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Catalog of the hitherto known plants in the United States/Folia plantarum Lancastriensium, Page 10 by Henry Ernest Muhlenberg. Courtesy of the American Philosophical Society.

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As the nickname "Keystone State" implies, Pennsylvania played a central role in America's path to independence. As we contemplate the 250^th anniversary of the Declaration of Independence, let us also consider Pennsylvanians' pivotal contributions to the body of American plant knowledge. Several individuals stand out for their ability to apply keen observational skills, information from Indigenous people, and scientific nomenclature to identifying and classifying plants found in this "new" nation: John Bartram, his son William Bartram, and Reverend Henry Ernest Muhlenberg.

America's semiquincentennial provides an opportunity to recognize the early contributions of the Bartrams and Muhlenberg to the field of botany and to those who helped them in their endeavors. It is important to note that the contributions of these individuals to botanical knowledge relied upon the willingness of Indigenous people to share their intimate knowledge of native plants and their uses with them. It is also important to note that, like many of America’s "founding fathers," the Bartram and Muhlenberg families made use of the labor of enslaved and free Black individuals. (It was not until 1780 that the Pennsylvania Act for the Gradual Abolition of Slavery was passed.) The historical record indicates that John Bartram may have owned a Black man known only as Harvey, who worked his entire life on John Bartram's farm. Though some accounts maintain that Harvey was enslaved, then finally freed by John Bartram, recent research conducted at Bartram's Garden historic site maintains that Harvey was a free Black man. What is known is that John did purchase six enslaved people in Charleston, South Carolina, for his son William's East Florida plantation—a short-lived venture. Accounts of William's journeys reveal that enslaved individuals lent from local landowners helped pilot his botanical expeditions. Henry Muhlenberg's brothers, Peter and Frederick, were enslavers, but Henry himself was not.

Read on to learn how John Bartram, William Bartram, and Henry Muhlenberg each played a role in sharing knowledge of newfound plants in America with the world.

John Bartram (1699–1777)

Early life and background: John Bartram was born into a Quaker family near Darby, Pennsylvania. His mother died when he was very young, and his father, William, was killed in the Tuscarora War in 1711. After his father's death, his stepmother moved the family to Philadelphia. John had no formal education and considered himself a farmer. Around 1728, supported by a family inheritance, he established a farm on the banks of the Schuylkill River, near present-day Philadelphia, and devoted a portion of it to the cultivation and study of medicinal plants.

Black and white line drawing of the residence of John Bartram. — "Residence of John Bartram, built with his own hands, a.d.1730." Courtesy of the American Philosophical Society

Contributions to botany: As a Quaker, John Bartram was predisposed to see the hand of God in nature. He was also pragmatic and desired to bring the best of nature to his farm to be grown under his control. He was initially interested in plants that had medicinal value. He traveled widely, seeking new plant species, including forays into the Haudenosaunee (Iroquoian) lands in New York, and to Delaware, Virginia, the Shenandoah Valley, the Carolinas, Georgia, and Florida. Bartram cataloged his discoveries using the Linnean system of nomenclature, and Carl Linnaeus knew of John Bartram's findings through indirect correspondence. Linnaeus dubbed Bartram "the greatest natural botanist in the world." John Bartram had a brisk exchange of seeds and plant samples with amateur botanist and London Quaker Peter Collinson. The exchange began as mutual gifts, but over time, Collinson recognized the value of plants from the "new world" and paid Bartram a "subscription" for shipments of seeds, specimens, and occasionally live plants. Although Collinson initially showed some impatience with Bartram's written observations accompanying the plant material, Collinson connected Bartram with European scientists and eventually helped Bartram secure the role of Botanist to the King (George III). As a Quaker, John Bartram was a pacifist and opposed war of any kind. He died in the very early years of the Revolutionary War.

Knowledge derived from Indigenous people: John Bartram seemed to have a general distrust of Indigenous people, probably due to the circumstances of his father's death in the Tuscarora War. However, he was known to hire members of local tribes to locate and collect samples, and he consulted them for their knowledge of plants as medicine.

Contemporary connections:

Bartram's Garden is a 50-acre park located on the site of John Bartram's farm in southwest Philadelphia. It is operated by the non-profit John Bartram Association in partnership with the Philadelphia Department of Parks & Recreation. The Bartram family's stone house is open for special events.
Many shrubs and trees found in the Bartram Family catalog have become popular landscape choices, including: Carolina allspice (Calycanthus floridus), great laurel or great rhododendron (Rhododendron maximum), and Virginia sweetspire (Itea virginiana).

William Bartram (1739–1823)

Early life and background: William Bartram was one of 11 children of John Bartram; his mother was John Bartram's second wife, Ann Mendenhall. His brother, John, Jr., born in 1743, continued the family nursery business. William's early interest in natural history is demonstrated by his detailed drawing of a small brown bird that his father sent along to Peter Collinson with plant material in 1753.

Contributions to botany: In many ways, William added to his father's discoveries and classifications of plants in America; he also made unique contributions. While his father, John Bartram, made simple drawings of plants along with his field notes, William became an accomplished botanical and zoological illustrator. He began his research efforts by traveling with his father and undertook his own research journey through the American Southeast from 1773 to 1777. His journey was funded by English physician Dr. John Fothergill, who was a friend of Benjamin Franklin. William Bartram's book, Travels (published in 1791), chronicles this journey and is regarded as one of the first natural histories of the new republic. In addition to illustrating and cataloging plants in Travels, William Bartram writes about the interconnectedness of plants, animals, and the land, foreshadowing the study of ecology.

Color drawing of a white flower with a yellow center surrounded by ovate green leaves. — *Franklinia alatamaha*, (no date), by William Bartram. Courtesy of the American Philosophical Society, Violetta Delafield-Benjamin Smith Barton Collection

Knowledge derived from Indigenous people: Williams Bartram displayed a high regard for Native peoples and respected their vast knowledge of natural history. He eagerly consulted the Cherokee, Creek, Muskogee, and Seminole people for plant use information, particularly medicinal uses. He wrote Observations on the Creek and Cherokee Indians in 1789, though it was not published until long after his death.

Contemporary connections:

Discovery of the Franklin tree, Franklinia alatamaha, is credited to William Bartram, though it was first encountered by both John and William Bartram near the Altamaha River in what is now Georgia. This beautiful tree with late summer white blooms has been likened to a camellia. William named it in honor of Benjamin Franklin; however, the name was first published by another early Pennsylvania botanist, Humphry Marshall, a cousin of John Bartram living in Chester County, Pennsylvania. Marshall's opus Abrustrum Americanum (1785) was actually the first published natural history of the United States. Interestingly, the last Franklin tree in the wild was reportedly observed in 1803, so all the trees that exist today are descended from seeds collected by William Bartram. Today, you can see Franklinia specimens thriving at Bartram's Garden and many other Pennsylvania botanical gardens, such as Morris Arboretum and Gardens, Longwood Gardens, and the campus of Franklin & Marshall College.
In the 1970s, environmentalists sought to reconnect with William Bartram's environmental journeys by reconstructing the route published in Travels. Trails retracing Bartram's steps now exist in North Carolina, South Carolina, Georgia, Florida, and Alabama. A trail called Bartram's Mile wends along the Schuylkill River in Philadelphia, honoring his memory.

Henry Ernest Muhlenberg (1753-1815)

Though baptized as Gothilf Heinrich Ernst Muhlenberg, the botanist is usually known by his English name, Henry Ernest. His father, Henry Melchoir Muhlenberg, was a Lutheran minister who emigrated from Germany and is credited with founding the Lutheran Church in America. The elder Henry Muhlenberg married Anna Maria Weiser, the daughter of colonial leader Conrad Weiser. Henry Ernest was one of eleven children, and the Muhlenbergs became a prominent American family whose members held influential roles in politics, the military, religion, and academia. (Henry’s brother, John Peter Gabriel Muhlenberg, was a Revolutionary War general and statesman; his brother Frederick Augustus Conrad Muhlenberg was the first speaker of the U.S. House.) Though born in Trappe, Montgomery County, Pennsylvania, Henry Ernest Muhlenberg received his Lutheran theological education in Germany. In addition to his notoriety as a minister and botanist, Henry Ernest was the first president of Franklin College, now part of Franklin & Marshall College.

Oil painting with a man in a white wig and a balck robe. — Rev. Gotthilf Henry Ernest Muhlenberg by Jacob Eichholtz. Courtesy of Franklin & Marshall College and the Phillips Museum of Art Collection, Lancaster, Pennsylvania. All rights reserved.

Contributions to botany: Henry Ernest Muhlenberg was the pastor of Trinity Lutheran Church in Lancaster from 1780 until his death in 1815, and it was here that he pursued his interest in botany. He traveled the nearby countryside, collecting and classifying specimens. In a 1791 letter, he related that he had collected more than 1,100 different plants. Muhlenberg made painstaking use of the Linnean system to classify his findings. He is known for connecting with botanists and scientists of his day, especially as he sought to ensure that his plant discoveries were original. His correspondence also led him to research and classify species that he would never encounter in person, which he preserved in his own herbarium. His interest in grasses from the Southwest and Mexico led to the naming of the genus Muhlenbergia. Muhlenberg's publications included an 1813 work that was often referenced by later botanists: Catalogus plantarum Americae Septentrionalis: huc usque cognitarum indigenarum et cicurum (A catalog of the hitherto known native and naturalized plants of North America, arranged according to the sexual system of Linnaeus).

Knowledge derived from Indigenous people: Both the period of Muhlenberg's botanical activity and his propensity to stay close to his home base of Lancaster meant that accessibility to plant knowledge of Indigenous people was far less than the Bartrams'. The Susquehannocks, who had once thrived in the Lancaster area, were decimated by disease and war by the late 1600s, with the majority of their descendants killed by white settlers in 1763. According to an unpublished paper by Dr. Tanya Kevorkian of Millersville University, Muhlenberg sought out and recorded at least 30 Indigenous uses of regional plants. However, his information was undoubtedly secondhand from white associates.

Contemporary connections:

Botanical names of many native plant species incorporate muhlenbergii (or muehlenbergii) to honor Henry Muhlenberg's contributions to botany. Examples include chinkapin oak (Quercus muehlenbergii), a moderately-sized oak with leaves similar to chestnut trees, and pink muhlygrass (Muhlenbergia capillaris), a perennial grass for landscapes with pink, cloud-like panicles.
In Lancaster County, the Muhlenberg Botanical Society is named in Henry Muhlenberg’s honor. It seeks to foster appreciation and understanding of native plants and to preserve their habitats.

The American Philosophical Society in Philadelphia is an important, enduring resource that connects all three American botanists discussed here. It is the repository for letters and botanical illustrations by Henry Ernst Muhlenberg, materials from other members of the Muhlenberg family, and catalogs and documents pertaining to the work of John and William Bartram, including William's drawings. These are preserved and made available for research, both on-site and online. Founded in 1743 by John Bartram and Benjamin Franklin as America's answer to the Royal Society in London, this institution is an invaluable resource for modern scholars. For more information, see the American Philosophical Society.