Fig 3. ndh gene length variation among orchid plastomes.

Numbers within cells refer to gene or pseudogene lengths. Key to colored cells: white—full-length, in frame; yellow—pseudogenized (very short, frame-shift inducing indels); blue—truncated (significant indels); red—completely deleted. The lengths of ndhA and ndhB include their introns. Taxa are presented in the same order as in Fig 4. Gene lengths are not provided for Apostasia wallichii because in some cases, small portions of the 5′ or 3′ ends of the genes were not sequenced and were hence unavailable in GenBank; likewise, only coding sequences were available (no introns were included) for the two intron-containing ndh loci [19].