Dig deeper at SERNEC, a consortium of southeastern herbaria.
R. viscosum is a member of what the Azalea Society of America refers to as "the white group". Read more here.
Read more about R. viscosum at Vascular Plants of North Carolina.
Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Asterids: Ericales
Manual of the Southeastern Flora (Small, 1933)