Sunday, March 19, 2017
The Flower that Grows on Walls - Cymbalaria muralis, Pennywort
Left: Cymbalaria muralis (Pennywort) on a wall. Right: A wall in the third cloister of Convento di San Francesco (Bergamo) where pennywort grows. The wall looks north.
To say this plant is ubiquitous is an understatement. It’s one of the first plants I’ve noticed when we landed in Bergamo. A year later, I find myself at the ex-Convento di San Francesco on a warm Sunday morning staring again at this plant blooming and finally decide to investigate.
It’s got a number of suggestive common names as detailed on the U.S. National Plant Germplasm Site: coliseum-ivy, ivy-leaf-toadflax, mother-of-thousands, Oxford-ivy, pennywort, wandering-sailor, and others. I personally like pennywort, so I’ll use that here when referring to a common name. In Italian, it is commonly called ciombolino comune.
Cymbalaria muralis is native to south and southwest Europe. Some references place pennywort in the plantain family (Plantaginaceae) and others in the figwort family (Scrophulariaceae). The little labiate flowers, usually rose to violet colored add a happy accent to any wall.
The success of this plant, according to Plant Tropisms: And other Growth Movements (J.W. Hart, p. 101), it due to its curious behavior in respect to light, or phototropism. “After fertilization the previously phototropic stalk bends away from the light to the extent that the ripening seed pod becomes buried in some dark crevice…” like the wall in the Convento di San Francesco, a structure that dates back to the 13th century in Bergamo’s upper city. I wonder what the friars there called this plant?
Left: The third cloister at Convento di San Francesco, looking into second cloister called the Chiostro del Pozzo. Right: View of the main cloister, Chiostro dell Arche.