In this first major book on New Guinea orchids since 1928, O'Byrne deals with species found growing below 1000 metres altitude in Papua New Guinea, a country which comprises the eastern half of New Guinea and over 1400 other islands. Some 950-1000 orchid species have already been recorded from the PNG lowlands; 269 species (from 55 genera) are fully described in this book. Each species is illustrated with line drawings and over 130 of them are also illustrated in colour.