the bare tree
Bellini describes a number of trees in the St Francis painting, including significant underdrawing of a tree recently discovered by the Frick collection using infra red technology. This suggests he originally intended to show the saint standing in a wooded environment or next to a tree. His landscape composition may have changed following the underdrawing, but the inclusion of tree imagery is subtly maintained throughout the picture space.
In the background, we see a tree masking a hill town. Unlike the rest of the plants and small trees in the saints immediate rocky landscape, this tree is bare. Why? The time of day and season is ambiguous, with some of the plants flowering in the foreground, others seem dormant, and here a curious, bare tree. Perhaps this is symbolic, like many of the other plants described in the landscape. The song or verse St Francis's may be saying (he is open-mouthed suggesting his is speaking) could be causing the landscape around him to transform. Light enters the landscape causing the plants like the laurel to bend towards him and small flowers on the edge of the bank to open up.
The shepherd's world in the background is yet to be touched by this divine light, he can only look on at what is happening in St Francis rocky world, but there is hope of transformation and new life to come in the image of the bare tree.