Fig. 2

Intron content of liverwort mitochondrial genomes. The species are ordered as in the phylogeny in Fig. 3. The black circle indicates the presence of an intron; the white square the absence of an intron. Intron nomenclature follows Dombrovska and Qiu (2004) and Knoop (2004). The number of species analyzed for each genus is indicated in the bracket following each genus’s name. The numbers at the bottom of each column indicate the total intron number