Gene map of the Welwitschia mirabilis plastome. Genes shown on the inside of the circle are transcribed counterclockwise and those on the outside clockwise. Gene boxes are color coded by functional group as shown in the key in the figure. The genome shows a structure typical to most chloroplast genomes: two copies of the inverted repeat region separating the large and small single copy regions. There are, however, multiple gene-order changes and gene losses relative to the ancestral genome organization, as well as slight expansions of the IR at the LSC and SSC boundaries.
McCoy et al. BMC Evolutionary Biology 2008 8:130 doi:10.1186/1471-2148-8-130