26 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 53 THE GENERA OF JUGLANDACEAE IN THE SOUTHEASTERN UNITED STATES1 THOMAS S. ELIAS JUGLANDACEAE A. Richard ex Kunth, Ann. Sci. Nat. 2: 343. 1824, "Juglandeae," nom. cons. (WALNUT FAMILY) Trees [rarely shrubs] mainly of temperate regions, the branchlets terete,the wood durable, often dark-colored. Leaves deciduous [or evergreen],alternate [or opposite], petiolate, imparipinnate, usually glandular-dottedbeneath and aromatic, exstipulate. Flowers imperfect. Staminate flowersborne in pendulous [rarely erect] aments, 3-to several-fasciculate onbranches of the previous year or at the base of branches of the year, orsolitary and lateral [or borne in a terminal cluster of several pendulousor erect aments with a central carpellate ament]; each staminate flowerwith a primary bract,2 2 secondary bracts [sometimes absent], and 4 orfewer perianth lobes, or the perianth sometimes absent (Carya, Platy-carya); stamens 3-100, attached to the receptacle and borne in 1 to sev-eral series, the filaments short, free, the anthers basifixed, erect, 2-locular,with longitudinal dehiscence, a rudimentary gynoecium occasionally pres-ent. Carpellate flowers borne [on a central ament in a terminal clusterof staminate aments or] on a solitary [pendulous to] erect, often few-flowered spike, each sessile flower composed of a floral envelope andgynoecium, the floral envelope consisting of an involucre composed of a 'Prepared for a generic flora of the southeastern United States, a project of theArnold Arboretum and the Gray Herbarium of Harvard University made possiblethrough the support of the National Science Foundation (Grant GB-6459X, princi-pal investigator Carroll E. Wood, Jr.). This treatment follows the format establishedin the first paper of the series (Jour. Arnold Arb. 39: 296-346. 1958). The area ofthe flora includes North and South Carolina, Georgia, Florida, Tennessee, Alabama,Mississippi, Arkansas, and Louisiana. The descriptions are based primarily on theplants of this area, with additional information about extraterritorial taxa inbrackets. References that I have not seen are marked by an asterisk. I am grateful to Dr. Wood for his thorough editing, valuable suggestions in thecourse of this study, and the several weeks he devoted to the manuscript. Dr. DonaldE. Stone has read the manuscript and has offered a number of useful and much-appreciated comments. Mrs. Nancy Dunkly has helped greatly in checking the bibli-ography and typing the manuscript. The illustrations are by Virginia Savage, large-ly from materials from the Arnold Arboretum supplemented by some preserved ma-terial of Carya kindly sent by Dr. Stone. SThe primary bract of Alfaroa and Engelhardia (geard ) is 3-lobed and isinterpreted by Hjelmqvst (1948) as representing the fusion of two lateral secobracts with the primary bract.