As previously stated, sweetbay in the northern portions of its  range is basically a shrub and becomes more treelike in the  southern portions of its range. There is no information readily  available on race differences of sweetbay.

    A hybrid cultivar, Magnolia x thompsoniana, which  is intermediate in character between M. virginiana and  M. tripetala, is grown as a garden plant in the Eastern  United States and in Europe. It was first raised in an English  nursery more than 200 years ago (21). No varieties of sweetbay  are recognized (14).