The Chilean Guava is often listed as Myrtus ugni. It is native to Chile and southern Argentina and is a charming evergreen shrub with small glossy opposite leaves and white flowers. It is best known for it's tasty sweet cranberry-like fruit sometimes called "Ugniberry". It is hardly known in the southern U.S though perhaps better known in the Pacific Northwest. It deserves to be tried in zones 8 and 9 where it would probably be best in somewhat sandy acid soil. In the South where summers are hot it should probably be shaded from the hot afternoon sun.
USDA Hardiness Zone 8-9