On 22 March 1736/37, the Quaker naturalist and linen merchant Peter Collinson composed a letter from London for his correspondent in the American colonies, the botanist John Bartram. Collinson directs Bartram to collect a parcel that Collinson has sent through an intermediary in Philadelphia. The parcel contains a box of seeds and several other letters—two for Bartram and additional letters he is to deliver to Collinson’s other colonial correspondents. As a token of his appreciation, Collinson includes in his letter the following botanical gift and instructions: A postscript reminds Bartram of the letter’s delicate seed enclosure—“take Care Some Seeds in the Letter.” Even a small quantity of seeds substantially increased the cost of a letter; Collinson advises Bartram that he “[considers] Double postage to have putt 1/2 doz seeds in this Letter.” Because loose seeds would undoubtedly spill out of a sealed letter when opened, Collinson likely placed the six precious seeds of the “Oriental Persicaria” first in a folded paper packet [see figures 1 and 2], which he then enclosed in the letter. We have, in Collinson’s letter, a window onto seed exchange as it was practised between private individuals during the long eighteenth century. Conducted alongside the commercial market for plants, such private seed transfers were not without their own tangible costs. They required a social network, an epistolary apparatus, some spare paper for fashioning seed packets, as well as patience and imagination. In the essay that follows, I explore the material and textual practices associated with seed exchange between individuals. While correspondence by Collinson and other eighteenth-century figures with horticultural interests has survived in manuscript form, letters rarely, if ever, still preserve their original seed packets. Once a correspondent in the eighteenth century took receipt of a seed packet, its contents were likely swiftly sowed in the garden or divided further among intimates. If a manuscript letter did preserve its original seed packet for a period of time, once it arrived in an institutional archive or library, its organic matter meant that it was usually disposed of or at least separated from the letter. Thus, while it has been possible to reconstruct some of the dynamics of seed exchange using eighteenth-century correspondence, the precise material features and contexts of “some seeds in the letter” have remained largely out of view. Where eighteenth-century plant and seed transfer has been treated by scholars, British imperial projects have provided the central framework. The essays in Visions of Empire: Voyages, Botany, and the Representations of Nature (1996) trace how the drive to identify new profitable species for the empire spurred the diffusion of plant material associated with the journeys of Joseph Banks and James Cook. In Natures in Translation: Romanticism and Colonial Natural History, Alan Bewell expands on a point made earlier by David Philip Miller about the mobility of natural history specimens. For Bewell, the British identity in the eighteenth century and beyond was rooted in the nation’s “capacity to mobilize people and things.” Taken together, an article by Christopher Parsons and Kathleen Murphy (2012), and an essay by Mark Laird and Karen Bridgman (2014) provide much useful information about the practicalities and rhythms of transporting plant specimens across the Atlantic. The social and commercial dynamics of botany in the decades around 1800 have been reconstructed recently by Sarah Easterby-Smith. A. Marples and V.R.M. Pickering have discussed the ways in which botanical objects, specifically those in Hans Sloane’s collection, were especially unstable and how organizational systems were developed during the early modern period to manage this knowledge. Like the above treatments, my essay is concerned with strategies for making …