Orchid flower (Pterostylis nutans), seen from the side. The distinctive hooded shape of the flower is formed by an overhanging dorsal (upper) sepal. The lip (the specialised petal of an orchid that attracts pollinators) is hinged and moves in the wind to give access to the reproductive parts. It is seen here as the curved flap at left of the large hood. This orchid is found in New Zealand and southern Australia. It is a terrestrial orchid (one that grows in the ground). There are more than 30,000 species of orchids worldwide, many of which are grown as ornamental flowers.