Figure 2. Comparison of the boundaries of large single copy (LSC), small single copy (SSC) and inverted repeat (IR) regions in Arabidopsis thaliana, Gynostemma pentaphyllum, three Begonia species and Hillebrandia sandwicensis. In contrast to the plastome sequences of Arabidopsis thaliana and Gynostemma pentaphyllum, those of most Begonia sampled in the present study (here represented by B. fenicis) and Hillebrandia sandwicensis have identical plastome structures, with an IR expansion (labelled '1st Expansion') resulting in an approximately 11-kb duplicated fragment. Begonia ulmifolia has another 153-bp IR expansion (labeled '2nd Expansion') from IRb to LSC and including a partial rps19 sequence. The published plastome of Begonia guangxiensis (Dong et al., 2019) includes contracted IRs, similar to those of Arabidopsis thaliana and Gynostemma pentaphyllum. The grey box represents the range of IR. An asterisk indicates that the gene carries an intron.