Cover Caption:
Orchidaceae are one of two largest plant families and contain ~28,000 species with beautiful flowers. Among them, more than 20,000 species grow on trees as epiphytes. In this issue, Zhang et al. (pages 1204-1225) present nuclear phylogenetic trees of 610 orchid species using 639–1,195 single/lowcopy nuclear genes, resolving phylogenetic relationships among most tribes and subtribes. Further analyses suggest multiple parallel origins of epiphytic orchids and their diversification might have been promoted by angiosperm rainforests. The cover shows diverse flowers of both epiphytic and terrestrial orchids.[Detail] ...