The "White Group" contains R. alabamense, R. atlanticum, R. arborescens, R. viscosum (which now includes R. oblongifolium and R. serrulatum), and our newest species, R. eastmanii. The azaleas in this group are not necessarily pure white since there may be forms that are shades of light pink. All of the species in the White Group are delightfully fragrant which adds to their appeal as great garden plants.
If I were to select my favorite from this group it would be R. arborescens because of its pristine white flowers with striking red stamens, and its powerful heliotrope fragrance that perfumes the entire yard. There is an excellent selection of R. arborescens by Clarence Towe called "White Lightning". It has huge white flowers with distinctive red stamens, a yellow blotch, and that delicious fragrance so characteristic of the species. Some believe that "White Lightning" is a natural hybrid of R. arborescens with R. cumberlandense, but whether hybrid or species, this variety is surely one of the best of the best, a superior plant in any garden. There are some wonderful stands of R. arborescens at the top of Wayah Bald in North Carolina, and along many waterways in the east including the Cheat River in West Virginia. Arborescens usually grows near moist areas, but one is usually aware that the plant is nearby long before seeing the blooms because of that wonderful fragrance.