Are there plant and flower images?
It is unlikely. Similar to the claim that there are coin images on the Shroud as well as letters and even parts of proclamations, they are probably pareidolia caused by excessive grain in camera film. Shadows from the threads and darker and lighter bands that are characteristic of the cloth and these features are exaggerated by the camera and the methods of lighting used. There are two images that look like petal-shaped flowers. One is fairly easy to see. The other one is more difficult. But that doesn’t mean they are images of flowers. They seem more like a young child’s drawings of a flower. However, pollen grains found imbedded in the cloth seem to offer support of the claim of plant images. Apparently, these plants only derive from the environs of Jerusalem. It seems to be a powerful argument for authenticity. But is the identification of those pollens is also questioned. The burden of proof that the images are there belongs to those who claim to see them. That burden has not been satisfied.
See also: Coin images and the Pantocrator Icon from St. Catherine's Monastery in the Sinai.