Lindsay Bourque wrote today’s entry:
Pulmonaria, commonly known as lungwort, has a long history as a garden plant as a fixture in the medieval physic garden. Believing that the spotted leaves of Pulmonaria represented diseased lungs (pulmo – Latin for lung), lungwort was used for centuries to treat ulcerated and diseased lungs based on the idea of sympathetic magic, which became formalized in the Doctrine of Signatures. Now primarily grown for its ornamental value, one of the charms of this shade-loving plant is the change in floral color from pink to blue. The cultivar in today’s photo, ‘Roy Davidson’, a hybrid between European species Pulmonaria saccharata and Pulmonaria longifolia, has a more consistent flowering color and is also cultivated to be mildew resistant as powdery mildew can be a problem in both of the parent plants.
The change in floral color is thought to be a pollination indicator to bees (who are the primary pollinators of lungwort) and who are also very sensitive to the ultraviolet light spectrum—the change of floral color indicates to the pollinator when the pollen and nectar are ripe for the taking. If you’ve ever looked closely at the species, you may have also noticed that some stamens extend beyond styles and some that don’t—this isn’t random variation but rather what is termed heterostyly—a characteristic that ensures cross-pollination of the pin flowers and thrum flowers.