Biological Flora of the British Isles: Ophrys sphegodes

This account presents information on all aspects of the biology of Ophrys sphegodes Mill. that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characteristics, herbivores and disease, history and conservation. Native to Britain, O. sphegodes used to be more widely distributed throughout south‐eastern England, but is now mainly restricted to the counties of Dorset, East Sussex and Kent. It is widespread throughout the western parts of central and southern Europe, and is common in Spain, France and Italy. Further east, it occurs in Bulgaria and Greece, including most of the Mediterranean islands, and extends into southern Russia, Turkey and northern Iran. Ophrys sphegodes grows on calcareous, nutrient‐poor substrates and rarely under any shade. It is most common in ancient, heavily grazed grassland on chalk and Jurassic limestone, but it also occurs in disturbed habitats, horizontally oriented rock floors in limestone quarries, on old limestone quarry spoil heaps, and in lightly trampled calcareous grasslands on maritime cliffs. Ophrys sphegodes multiplies predominantly by sexual reproduction. Vegetative multiplication occasionally occurs through survival or splitting of the old tuber. In the UK, the species is almost exclusively pollinated by males of the solitary bee Andrena nigroaenea. Male bees are attracted by complex floral bouquets emitted by the flowers that strongly resemble pheromones produced by female A. nigroaenea. Fruit production is generally low, and in most populations,