Botanical explorers roamed temperate North American colonies long before André Michaux came to the United States. The efforts of these men and women accounted for thousands of new species of plants described in the scientific literature from the early 1500s until 1785 when Michaux arrived to begin his studies that would ultimately result, in 1803, in an abbreviated summary of the region's known flora. Most of the early collecting efforts concentrated on trees and shrubs of potential ornamental significance or plants of medicinal importance. Introduction of temperate North American plants was well underway by 1600, with a steady flow of natural objects going to Western Europe throughout the seventeenth century. Although broad, general interest in North American plants declined after 1700, the efforts of a few—notably Mark Catesby, John Clayton, John Mitchell, John Bartram, Pehr Kalm, Alexander Garden, Caldwaller Colden and William Bartram—greatly shaped Carl Linnaeus' understanding of our flora from 1735 until his death in 1778. Therefore, Michaux did not enter into an unexplored wilderness where everything was new but rather a land that required a naturalist with a broad understanding of what was undiscovered still. The focus of this paper is to review the effort of those early naturalists, and to present details of the new methods Michaux brought to field botany: A broad knowledge of plants, a genuine willingness to explore, and a desire (albeit reluctant) to put what he knew into print. Unfortunately, his ultimate product, Flora Boreali-Americana, was myopic in scope and therefore woefully incomplete because Michaux failed to consult the wealth of material collected prior to his own efforts.

This paper situates André Michaux's American career in the larger context of contemporary French botanical institutions. An extensive set of botanical gardens in metropolitan France included the Jardin du Roi (1635) in Paris and several dozen other gardens spread throughout the provinces. A complementary system of botanical gardens and horticultural stations arose outside the Metropolis in the colonies. In the 1750s, French authorities established spice cultivation in the Indian-Ocean settlements on Île de France (Mauritius) and Île Bourbon (Reunion). By the 1770s and 1780s, royal botanical gardens had spread to Cayenne, Guadeloupe, and Saint-Domingue (Haiti) in the New World. In the 1780s, the Ministry of the Navy undertook several botanical transfers from the Indian Ocean to the Americas with the aim of implanting commercial cultivations in the New World. André Michaux's expedition to North America formed part of this larger network. Had the French Revolution not intervened, the American gardens founded by André Michaux might have been further swept up in this unprecedented intercontinental system of French botanical stations.

French botanist André Michaux (1746–1802) is well known in botanical history. Working on behalf of France, he spent the years 1785–96 in North America where he traveled widely, explored frontier areas not visited by earlier botanists, and discovered hundreds of plant species new to science. Perhaps the least understood episode of his career concerns his participation in the shadowy political and diplomatic tangle known in U.S. history as the “Genet Affair.” In 1793, the French Minister to the U.S., Edmond Charles Genet (1762–1834), attempted to clandestinely raise an army of frontiersmen under the leadership of General George Rogers Clark for the purpose of driving the Spanish out of Louisiana. Acting on Genet's instructions, Michaux traveled to Kentucky and participated in this enterprise. It has been suggested that Michaux may have used Genet's mission as a means to travel to Kentucky to botanize; he was first and foremost a botanist. Evidence is presented that Michaux embraced the mission as a French patriot and made strenuous efforts to carry out his instructions.

André Michaux was a trained botanist who visited North America for eleven years (1785–96) as royal botanist specifically sent to collect plants for France. His explorations resulted in a large collection housed today in the Museum National D'Histoire Naturelle, Laboratoire de Phanerogamie (P), Paris. Michaux collected thousands of specimens for cultivation in his Charleston garden and shipment to France. In addition, he pressed many examples of his collections for inclusion in his herbarium and kept an extensive journal of his activities while in North America. This study concentrates on his activities in the Carolinas. His plant names and descriptions were published as Flora Boreali-Americana in 1803, the year after his death. This publication was not only the first North American flora but also unique in that all the plants described were collected personally by Michaux.

André Michaux was named royal botanist to King Louis XVI of France in 1785. His mission to North America was to collect plants, seeds, and other useful products of natural history to restore France's forests and enrich the royal gardens and parks. From his Journal of My Voyage, a record of his daily activities kept during the 11 years in America, we can retrace his steps, determine what plants he observed and collected, and learn whom he met. Michaux arrived in St. Augustine, Florida, on February 28, 1788, with his son, François André, and a young servant. The Second Spanish Period (1784–1821) of Florida history was in its fourth year. After visiting Governor Vizente Manuel de Zéspedes, the Governor offered Michaux assistance and permission to travel in Spanish East Florida. Michaux purchased a canoe and provisions and hired two oarsmen for a trip south along the east coast of Florida. He left with his entourage on March 12, and did not return until five weeks later, having traveled on horseback, canoe, and on foot to today's Cape Canaveral. Michaux wrote in his Journal on April 27 that 105 species of plants had been found since March 1, his first day of collecting in Florida. Forty species were well known to the botanist, 36 were of genera he knew whose specific epithet he was unsure of or did not know, and 29 plants were not determined because they were not in flower. The number of species Michaux found after April 27 is not recorded. The Michaux party left St. Augustine on April 29 for the St. Johns River. He canoed up the river to south of present-day Blue Spring, Volusia County. Michaux wrote that the trip to Florida was fruitful. His collections yielded several new species: Sphenopholis obtusata, Fimbristylis spadicea, Furiena scirpoidea, Rhynchospora ciliaris, and Ceanothus microphyllus.

This paper highlights André Michaux's journey in Canada at the end of the Eighteenth Century. On June 7, 1792, André Michaux left New York City for Canada. He sailed up the Hudson River and pursued his itinerary to Lower Canada. Michaux's intention was to reach Hudson Bay. His scientific expedition consisted of analyzing the geographical distribution of North American plants and determining their habitats. From the Hudson River to the Rivière Mistassini (Canada), he described the natural beauty of the Appalachian Mountains (United States), lakes and rivers; he traveled through the Laurentian Mountains (Canada); he continuously observed and collected plants on his scientific expedition; and he identified animals that he specifically noticed between Lac St-Jean and Lac Mistassini. These principal aspects of his journey in Canada from June to November 1792 were the prime concern for this study.

Biographies of André Michaux and his own work depict him more as a man of action than of contemplation. A careful reading of his writings, however, reveals not only a busy botanist but also a sensitive observer of religions, not only an intrepid explorer but also a man possessed of some fears. This paper examines Michaux's worldview that underlay his complex character, his understanding of God and nature as evidenced in his journals and letters. It offers the thesis that Michaux's religion intriguingly combined Enlightenment Natural Religion with popular French Catholic piety.

Following an unsuccessful attempt at establishing a botanic garden in New Jersey, André Michaux relocated to Charleston, South Carolina, in 1787 where he developed a plant nursery some ten miles outside the city. From this site, Michaux shipped a great number of North American plants and seeds to France and, in return, was permitted to import from the botanic gardens of France numerous trees and shrubs that had been collected from all parts of the world. Both from an historical and horticultural point of view, Michaux's Charleston nursery was important in that it was the location where many Old World and Asian plants first arrived in North America. Included among these introductions were the mimosa or silk tree (Albizia julibrissin), the tea olive (Osmanthus fragrans), the crape myrtle (Lagerstroemia indica), the ginkgo (Ginkgo biloba), the Chinese parasol tree (Firmiana simplex), tea (Camellia sinensis), and the camellia (Camellia japonica). Each of these introductions remains as an important ornamental in southern gardens today – both for contemporary use and as historic plants for period gardens and landscapes.

The name of André Michaux is associated with 742 vascular plant type specimens he collected in North America during the 1790s. While most of these species are widespread and familiar to most botanists, many are uncommon or rare. A selection of 19 rare Michaux plants are included here, with notes on taxonomy, present and past distribution, habitat, rarity status in each state, general population numbers and trends, and threats. The 19 species represent 17 plant families. The species vary from highly restricted endemics to geographically widespread; two of the species are Federally Endangered; nine are Federal Species of Concern. This small selection of plants stands tribute to the remarkable Michaux legacy of frontier exploration and botanical discovery.

In the spring of 1839, Asa Gray found a specimen bearing small scalloped leaves, without flowers, but with a scape with a calyx and capsule, in the Michaux collection at the Muséum d'Histoire Naturelle, Paris, which Michaux had labeled “An Pyrola spec? an genus novum? Hautes montagnes de la Caroline.” This plant was subsequently named Shortia galacifolia T. & G. Charles Sprague Sargent, after travel in the Carolinas and reading Michaux's journal, concluded that the type was collected in December 1788 at the forks of the Kiwi [Keowee] River, Oconee Co., South Carolina. Other botanists disagreed and maintained that the type was collected in June 1787 in the area of present day Jocassee Dam, also in Oconee Co., South Carolina, as there would be no remaining capsule in December. The specimen that Gray studied in Paris has disappeared. We have recently found an isotype of this species in the de Jussieu collection at the Paris herbarium. This one is labeled by de Jussieu: “Pyrola or related genus. In a specimen in the Michaux herbarium, we have seen a capsule which appears to be 3-valved, each valve had a partition in the middle. Given by Mr. Michaux in 1797, collected by him in 1787” (transl.). This specimen substantiates the correct date of collection and type locality for this taxon.

André Michaux collected a single specimen of Shortia galacifolia in1787, in Oconee County, South Carolina. Asa Gray found the specimen in the Michaux herbarium in Paris and searched for it on his return to the U.S. In 1886, Charles Sargent rediscovered Shortia in the Jocassee area of Oconee County, South Carolina, ending the long search for its location. The Jocassee area, the historical center of Shortia's population, was flooded by Duke Power Co. in the early 1970s and is now under Lakes Jocassee and Keowee. Less than 50 percent of the former habitat survives, now severely fragmented. The shoreline along Lake Jocassee was inventoried for Shortia. Of over a hundred clusters found, about 25 percent were considered in immediate danger of erosion from wave action. Most remaining Shortia are on the banks of streams feeding the lake. Elsewhere there exist small disjunct populations of this beautiful, threatened discovery of Michaux.

Magnolia macrophylla Michaux (Big-Leaf Magnolia) has the largest size simple leaf and flower of any North American tree. Its primary geographic range includes the southeastern U.S. In North Carolina, it is predominantly found in Gaston County, located in the western Piedmont region of the state. This geographic isolation from its more extensive range in more southern states probably represents a bottleneck effect after the last glaciation period. Data from eight population sites sampled from the 2000 to 2002 growing seasons show a significant correlation of M. macrophylla with more mesic habitats. Fagus grandifolia, Acer rubrum, Liriodendron tulipifera and Oxydendrum arboreum are important associate species within these sites. Periodic disturbance may be an important factor in the maintenance and establishment of M. macrophylla populations.

Populations of Magnolia macrophylla Michx. in Gaston County, North Carolina, and one in neighboring York County, South Carolina, were examined using allozyme analysis. All populations studied had the same monomorphic genotype. Several factors could account for this lack of variation. Migration from population centers along the Gulf Coast by sequential founder events could have resulted in populations at the northeastern limit of its range being genetically depauperate. Sexual reproduction in these populations is rare because most trees do not appear to live long enough to reach maturity. Recruitment of new individuals seems to be by vegetative reproduction of ramets from roots of immature trees. Any pollen exchange that does occur is between trees that represent another part of a single clone.

In 1794 André Michaux discovered dwarf sumac Rhus michauxii in Mecklenburg County, North Carolina, and in 1803 published a species description under the name Rhus pumila. In 1895 C.S. Sargent assigned the name R. michauxii to correct Michaux's use of a homonym and to honor its discoverer. The type location is now in Union County, North Carolina, which was formed from part of Mecklenburg County in 1842.

Michauxia honors André Michaux. It is a genus of herbaceous plants with an eastern Mediterranean and trans-Caucasian distribution. This paper is a brief introduction to the genus emphasizing its most spectacular member, M. campanuloides, which exhibits a distinctive form of dichogamy.

The 40,000 ha Wachovia (Wachau) tract, which encompasses much of modern Forsyth County, North Carolina, was surveyed by Reuter (1760–64), with subsequent surveys by Kramsch (1789–1791) and von Schweinitz (1821). Reuter's survey, despite its limitations, is valuable because it is the first record by a trained expert of the plant and animal species present during the European settlement of the piedmont frontier, predating reports from well-known pioneering botanists such as André Michaux, William Bartram and Asa Gray. A comparison of Reuter's list with a modern survey reveals that all the tree species he recorded are currently present in Forsyth County. Despite massive anthropogenic community disruption, there has been no loss of tree species diversity (measured as presence/absence) following European settlement. Due to the presence of introduced species, tree species richness is probably greater now than in 1764.

In the short time that he spent in Kentucky during 1793–1796, André Michaux visited five of the state's six geographic regions. The majority of his time, however, was spent in the Bluegrass, Knobs, and Pennyroyal Regions where his plant lists and landscape descriptions are the most thorough. Unfortunately, Michaux was acting more in the capacity of an agent for France than as a botanist while he was in Kentucky. Only when Michaux's plant lists are combined with the comments and landscape descriptions of other early naturalists can a partial description of the vegetation of Kentucky around the time of statehood in 1792 be achieved.

Stephen Elliott (1771–1830) published “A Sketch of the Botany of South-Carolina and Georgia” in thirteen fascicles, which were later bound in two volumes. Citations of Flora Boreali-Americana by André Michaux appear very frequently, and Elliott's remarks under numerous plants attest to his frequent reference to Michaux's Flora. At least one specimen in Elliott's herbarium bears Michaux's name. Michaux's holding garden near Charleston, South Carolina was well known to Elliott who visited it at least once. A map shows the site of “Old” Sister's Ferry used by Michaux and Elliott.

The date of André Michaux's death has been reported as both 1802 and 1803. Recently discovered archival evidence in Mauritius now confirms that 1802 is the correct date. Certain other facts about the life of André Michaux have not been reported previously. Archival evidence in France now reveals the date and place of André Michaux's marriage to Anne Cécile Claye, the dates of Anne Cécile Claye's birth and death, the location of Ann Cécile Claye's birth and death, and certain other previously unknown facts about Michaux's family.