A compendium of the flora of the northern and middle states, containing generic and specific descriptions of all the plants, exclusive of the cryptogamia, hitherto found in the United States, north of the Potomac.

Published after Torrey's appointment as profess or chemistry at West Point, in a small, handy format for botanical students, that "its small size will enable them to use it without inconvenience in their herborizations." Digital facsimile from Biodiversity Heritage Library at this link.