JOURNAL OF THE ARNOLD ARBORETUMTHE KRAMERIACEAE IN THE SOUTHEASTERN UNITED STATES i KENNETH R. ROBERTSON KRAMERIACEAE Dumortier, Anal. Fam. 20. 23. 1829, nom. cons. (RATANY FAMILY) A distinctive monogeneric family, mostly of arid regions in the NewWorld. The family is characterized by shrubby or herbaceous perennialhabit; exstipulate, simple and entire or rarely trifoliolate leaves; irregu-lar flowers; petaloid calyx that much exceeds the dimorphic petals; sta-mens confined to the adaxial part of the flowers; apically dehiscent anthers;bicarpellate gynoecium with one fertile and one sterile carpel; and spiny,one-seeded, indehiscent fruits. TYPE GENUS: Krameria L. Krameria is a quite singular genus, and its phyletic placement is prob-lematical. It has been treated by various authors as the sole member of Krameriaceae, of the Polygalales; as tribe Kramerieae, of the Polygalaceae; as Krameriaceae, of the Rosales; as subfamily Kramerioideae, of the Le-guminosae; and as tribe Kramerieae, subfamily Caesalpinioideae, of the Leguminosae. The structure of the wood, the exstipulate leaves, the vas-cular anatomy of the pedicel and receptacle, and the number and size of the chromosomes, as well as the frequency of chromosomal chiasmata, definitely indicate that Krameria is not closely allied to Leguminosae. Comparative information on Polygalaceae is mostly lacking, but three-or four-colporate pollen, adaxial stamens, collateral ovules, and seeds with endosperm are features never or seldom found in that family. Until more is known of Krameria and its supposed relatives, it seems best to keep the genus in its own family of uncertain affinities. 1. Krameria Linnaeus in Loefling, Iter Hisp. 195. 1758. Perennial herbs for, more often, low, much-branched, spinescent shrubs] from thick crowns on woody rootstocks; root system of long, few-branched taproots and/or horizontal lateral roots [some species root parasites]; 1 Prepared for a Generic Flora of the Southeastern United States, a joint project of the Arnold Arboretum and the Gray Herbarium of Harvard University made possible by the National Science Foundation (Grant GB-6459X, principal investigator, Carroll E. Wood, Jr.). This treatment, the seventieth to be published, follows the scheme outlined in the first paper of the series (Jour. Arnold Arb. 39: 296-346. 1958). The area covered includes North and South Carolina, Georgia, Florida, Tennessee, Alabama, Mississippi, and Louisiana. The descriptions are based on the plants in this area, with additional information from extraterritorial taxa in brackets. I am indebted to Professor Wood for his pertinent comments and to Ms. J. E. Hanhisalo for checking the bibliography and typing the manuscript.[VOL. 54
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