- sorrel tree, sourwood, titi, Oxydendrum arboreum - deciduous shrubby tree of eastern North America having deeply fissured bark and sprays of small fragrant white flowers and sour-tasting leaves
--1 is a kind of angiospermous tree, flowering tree
--1 is a member of Oxydendrum, genus Oxydendrum - sorrel tree, Hibiscus heterophyllus - Australian tree with acid foliage
--2 is a kind of hibiscus