Digitalis purpurea (L.) Plantaginaceae (formerly Scrophulariaceae)
Watercolour on vellum
The flowers of D. purpurea exhibit bilateral symmetry, thought to have has evolved as an adaptation to pollination by bees. The orientation of these zygomorphic flowers forces the pollinator to position itself within the flower in such a way that pollen is transferred onto the pollinators upperside (in an arrangement known as nototribic). In addition the long hairs on the floor of the corolla exclude virtually all other insects, and this ensures some specialisation within the species.
