Orchid flower (Angraecum eburneum). Angraecum orchids are tropical orchids that have green and white flowers. These have a complex structure with pointed sepals (green), petals (white) and a spur (a long tubular extension that usually contains nectar). The spur is seen running down to lower right from the base of the flower. The flower is growing on its vine (down left). The Agraecum orchids are found in Africa, Madagascar and the surrounding islands. There are more than 30,000 species of orchids worldwide, many of which are grown as ornamental flowers.