The flora of Western Australia (WA) is remarkably rich in orchids and includes some of the world's most attractive, colourful and unusual species. The beautiful butterfly orchid has large green, yellow and red flowers with a broad butterfly-like lip that vibrates in the slightest breeze and the blue lady orchid has flowers that are amongst the bluest of all flowering plants. WA also has two of just four underground orchid species – the famous western underground orchid and the south coast underground orchid. Field Guide to the Orchids of Western Australia provides photos and descriptions for all 39 genera and 430 orchid species currently known to occur in WA, including 323 that are formally named and 107 that are unnamed but are thought to be distinct. This is the first time all the known WA orchids, both temperate and sub-tropical, have been represented photographically in a single comprehensive publication.