Anyone who has studied the early history of Texas has stumbled at one point or another upon the figure of Jean Louis Berlandier. This Frenchman is best remembered as a botanist embedded — as we would say today — in the Comisión de Límites (Boundary Commission), an expedition of scientists appointed by Mexican president Guadalupe Victoria to survey the boundary between Mexico and the United States in the late 1820s. Russell M. Lawson has given us the first full biography of this indefatigable naturalist, beginning with his early life in eastern France and Switzerland, his training under the exacting Augustin Pyramus de Candolle at the Geneva Academy, his serendipitous appointment to the Boundary Commission, and his arrival to Mexico and initial travels. Lawson’s writing is engaging and evocative.The core of the book is devoted to Berlandier’s work in the Boundary Commission. Headed by General Manuel de Mier y Terán, a major political figure and an ardent nationalist, the commission spent several months traveling through Tamaulipas and Texas. Its mission was nothing less than to make an inventory of the mineral and botanical wealth of the region as well as to report on its intricate human geography, especially along the hotly contested Texas-Louisiana border. The memoirs, letters, and scientific texts written by commission members offer an unsurpassed view of prerevolutionary Texas. As Lawson recounts how the commission made its way through the modest Mexican towns, the thriving American colonies, and the Indian nations living in the region, we get a remarkably detailed glimpse of a world on the verge of tremendous change.The last section of Frontier Naturalist chronicles Berlandier’s decision to stay in the northwest of Mexico after his work with the Boundary Commission ended in 1829. Berlandier was an inveterate wanderer, so it is not entirely clear why he decided to settle in Matamoros. He made a living as a pharmacist and continued his scientific pursuits, collecting specimens and recording his impressions, although far less copiously than during his commission years. From his perch in Matamoros, Berlandier lived through an exceedingly eventful period in that region of Mexico, including the Texas Revolution of 1835 – 1836, the secession attempts of northern Tamaulipas in the late 1830s, and the initial stage of the US-Mexican War, which was fought within the Texas-Tamaulipas region. Berlandier survived the war, but in 1851 he drowned while trying to ford the Rio San Fernando some 90 miles south of Matamoros.Lawson imparts a wealth of contextual information while telling Berlandier’s interesting story. In this sense, Frontier Naturalist is not just a running account pieced together from Berlandier’s own writings but a far more ambitious biographical project that required a great deal of additional research. For example, the author places Berlandier’s botanical work in the context of a wider scientific community spanning Europe, the United States, and Mexico, provides very relevant information about the extent of the geographical knowledge about the Gulf Coast of Mexico in the early nineteenth century, and goes to great lengths to describe places like Tampico, San Antonio, Matamoros, and New Orleans. Especially valuable are the pages Lawson devotes to various indigenous peoples of the area, such as Tobosos, Carrizos, and Lipan Apaches. The French naturalist became especially familiar with some Kickapoo Indians who served as his guides and whom he described in considerable detail. Frontier Naturalist also includes luminous pages concerning the famous Comanches. Berlandier befriended José Francisco Ruiz, a Mexican Texan who had lived with the Comanches and knew them well, and together the two joined the horse people on a hunting expedition up through the Guadalupe River.Berlandier was first and foremost a scientist. As Lawson writes toward the end of his fine book, “Nature knows little of politics, and science must eschew such temporal distractions” (p. 191). Perhaps the only gap in this otherwise superb work is precisely a fuller discussion of the politics surrounding the Boundary Commission and, more generally, of the federalist-centralist rivalry that became so vicious and came to affect Berlandier’s life. After all, Berlandier owed his appointment to Lucas Alamán, the intellectual leader of the centralist faction, and participated in the Boundary Commission alongside General Mier y Terán, who ultimately recommended exercising greater military control over Texas and closing it off to further American immigration. However much Berlandier may have wished to stay out of politics, his centralist sponsors and contacts made it all but impossible. But apart from this partial omission, Frontier Naturalist is an engrossing tale and an enormously enlightening book.