Maximum likelihood tree. Composite individuals represent sections except in the case of sects. Rubra and Hyptiocarpa, where composite individuals represent species. See Table 1 for GenBank accession numbers. Boostrap values for nodes are shown in white circles. Purple circles to the right of species in sects. Rubra and Hyptiocarpa represent one set each of 26 chromosomes (i.e., 2n=26) and show ploidy levels in sects. Rubra and Hyptiocarpa (e.g., A. saccharinum is tetraploid). Color coding of red and blue among branches shows relative support, respectively, from high (=100%BS) to low (~0%BS). Branches are scaled according to the bar below the tree.