Clammy Azalea (Rhododendron viscosum). Ericaceae. August 10, 2020 1500 × 1200 Clammy Azalea (Rhododendron viscosum). Ericaceae. Also called Swamp Azalea. Native shrub. Acidic swamps, wetland edges. Napeague, June 2020. Native shrub. Acidic swamps, wetland edges. Napeague, Long Island, June 2020.