Canterbury Bellflower
The Merry Jesters, 1906
Henri Rousseau 
Oil on canvas 
Philadelphia Museum of Art 
Have you seen Henri Rousseau paintings, they seem child-like as if seen in a child’s book. In this painting, ‘The Merry Jesters’ we see a few bears and a bird; lots of greenery like the jungle and a few human-like objects. But in all that foliage, Rousseau painted a tall, single-stemmed, bell-shaped, white flowers. 
This flower is a Campanula medium, commonly known as Canterbury bells, or in short the Bellflower. This flower represents gratitude, or faith and constancy.
Henri Rousseau had never been to the jungle, which he depicted his in most of his paintings. From France, working as a tax collector, Rousseau had become resourceful, incorporating details inspired by his neighborhood, botanical gardens, zoos, paintings he had viewed at museums or images he had seen in books and magazines, transforming them into elements of his own visions.
The Campanula genus has around 500 species and linking many subspecies. The Campanula has been found across the temperate and subtropical regions of the Northern Hemisphere, such as around the Mediterranean, Europe, North America, and extends into mountains in the semi-tropical areas of Asia and Africa. The medium species originates in Southern Europe and is popular in the United Kingdom. 
The Latin name “campanula,” meaning “small bell” refers to the bell-shape of the flower. The Persian call the flower “Gol-e Estekani” meaning "Glass flower," which refers to its glass shape. 
These flowers come in vibrant blues and purples, and also white. The Campanula medium grows in the wild, but they are mostly cultivated in gardens around Europe and North America. They are used often in floral arrangements. 
The Canterbury bells in ‘The Merry Jesters’ so a vivid against the greenery, but can these flowers grow in the jungle? Probably not, the Bellflower needs ample amounts of sunlight during their time blooming and in bloom and do well in temperate climates and in the woodlands that have plenty of the sun. 
In the end, maybe Rousseau saw the Canterbury bellflower at the zoo right next to the bears...