Comparison of the sequenced genomes of the orchid species G. elata, P. equestris7, and D. officinale8,9 indicated that they diverged approximately 67 million years ago (Fig. 1b and Supplementary Fig. 4). Two ancient whole-genome duplication (WGD) events are evident in the G. elata genome; these events can also be discerned in the genomes of P. equestris and D. officinale suggesting they occurred prior to the divergence of the three orchid species (Supplementary Fig. 5). The older WGD event might represent the heWGD event10 shared by most monocots, while the younger WGD event were likely shared by all extant orchids and might contribute to the divergence of orchid, as suggested in Apostasia shenzhenica genome11.