The Marantaceae are a cohesive but taxonomically difficult group. The genera appear well-defined with few changes in circumscription over the recent decades. Relationships among the genera are poorly understood. The latest treatment above the rank of genus was that of Loesener in 1930, dividing the genera into two tribes based on the number of fertile locules. Andersson provided an informal treatment of the family in 1980, dividing the genera into five groups plus five genera of uncertain affinity based on a number of morphological characters. We sequenced the chloroplast matK gene plus flanking non-coding spacers and the trnL to trnF spacer region for 85 ingroup taxa representing 28 of the 31 currently recognized genera in the family. Additional sequences for 9 outgroup taxa representing the 7 other families of Zingiberales were included in the analyses. Our data do not support either of the above classifications although some of Andersson's groups are supported in part. A number of genera appear paraphyletic or polyphyletic based on our results including Phrynium, Calathea, and Schumannianthus. We evaluate the strength of the morphological features used for previous classifications and propose a provisional classification of Marantaceae.

Key words: Marantaceae, matK, phylogeny, trnL-trnF intergenic spacer