Tulip trees are a popular feature in parks and gardens. (a) The American tulip tree, Liriodendron tulipifera. Photo by Jean-Pol Grandmont. (b) Side view of a flower, the shape of which gives the tree its name. (c) Top view of a flower.
Small BMC Biology 2013 11:30 doi:10.1186/1741-7007-11-30