Submitted to: Plant Systematics and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 3, 2003
Publication Date: February 12, 2004
Citation: Meerow, A.W., Clayton, J.R. 2004. Generic relationships among the baccate-fruited Amaryllidaceae (tribe Haemantheae). Plant Systematics and Evolution 244: 141-155. Interpretive Summary: Using DNA sequences from chloroplast and nuclear, we studied the relationships with an African tribe of the amaryllis family that has berry fruits. This tribe includes the horticulturally important genera Clivia (African lily) and Scadoxus (Blood lily). Clivia and Cryptostephanus, both of which do not form bulbs, share common ancestry and form a group separate from the Blood lilies (Haemanthus and Scadoxus). The Blood lilies are most closely related to the genera Apodolirion and Gethyllis. The tribe probably originated in Eastern South Africa, with several subsequent migrations to the winter rainfall Western Cape region. Chromosomal change from is associated with each main group.
Technical Abstract: Using sequences from plastid trnL-F region and nrDNA ITS, we investigated the phylogeny of the fleshy-fruited African tribe Haemantheae 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 Cryptostephanus, 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 ancestral 2n = 22 (characteristic of Clivia) is associated with each main clade. Reduction in number has occurred in all but Cryptostephanus, which has 2n = 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 reflects Quaternary climatic changes in Southern Africa.