Generic relationships among the baccate-fruited Amaryllidaceae (tribe Haemantheae) inferred from plastid and nuclear non-coding DNA sequences A. W. Meerow 1, 2 and J. R. Clayton 1 1 USDA-ARS-SHRS, National Germplasm Repository, Miami, Florida, USA 2 Fairchild Tropical Garden, Miami, Florida, USA Received October 22, 2002; accepted September 3, 2003 Published online: February 12, 2004 Ó Springer-Verlag 2004 Abstract. Using sequences from the plastid trnL-F region and nrDNA ITS, we investigated the phy- logeny of the fleshy-fruited African tribe Haeman- theae of the Amaryllidaceae across 19 species representing all genera of the tribe. ITS and a combined matrix produce the most resolute and well-supported tree with parsimony analysis. Two main clades are resolved, one comprising the monophyletic rhizomatous genera Clivia and Cryp- tostephanus, and a larger clade that unites Haemanthus and Scadoxus as sister genera to an Apodolirion/Gethyllis subclade. One of four included Gethyllis species, G. lanuginosa, resolves as sister to Apodolirion with ITS. Relationships among the Clivia species are not in agreement with a previous published phylogeny. Biogeographic analysis using the divergence/vicariance method roots the tribe in Eastern South Africa, with several subsequent dispersals to the winter rainfall Western Cape region. Chromosomal change from an ances- tral 2n ¼ 22 (characteristic of Clivia) is associated with each main clade. Reduction in number has occurred in all but Cryptostephanus, which has 2n ¼ 24 chromosomes. Increasing the sampling across all of the species in the tribe will allow a more detailed understanding of the biogeographic patterns inherent in the parsimony topology, which undoubtedly reflect Quaternary climatic changes in Southern Africa. Key words: Amaryllidaceae, Haemantheae, geo- phytes, South Africa, monocotyledons, DNA, phylogenetics, systematics. Baccate fruits have evolved only once in the Amaryllidaceae (Meerow et al. 1999), and solely in Africa, but the genera possessing them have not always been recognized as a monophyletic group. Haemanthus L. and Gethyllis L. were the first two genera of the group to be described (Linneaus 1753). Her- bert (1837) placed Haemanthus (including Scadoxus Raf.) and Clivia Lindl. in the tribe Amaryllidiformes, while Gethyllis was classi- fied with Sternbergia L. in Oporanthiformes. Salisbury (1866) recognized the distinct tribes Haemantheae Salisb. and Gethyllideae Salisb. Bentham and Hooker (1883) united Crypto- stephanus Baker with Narcissus L. in their subtribe Coronatae, while maintaining Haemanthus, Clivia Lindl. and Apodolirion Baker in subtribe Genuinae. Cryptostephanus has perianthal appendages at the throat of the flower that Bentham and Hooker (1883) considered homologous to the corona of Narcissus. Pax (Pax 1887) situated Haeman- thus and Clivia in his subtribe Haemanthinae Plant Syst. Evol. 244: 141–155 (2004) DOI 10.1007/s00606-003-0085-z