Comparisons of the gene order of Alsophila spinulosa cp genome with other ferns. Comparison by using online zPicture software http://zpicture.dcode.org/. Points along the positive slope are in the same orientation in both genomes, whereas points along the negative slope indicate sequences that are oriented in opposite directions. A, the two groups of points that fall along the negative slope in the upper right corner represent the sequences of IRs. B and C, ellipses denote the complex rearrangements in IRs and arrows indicate the gene order change between rpoB and psbZ.