Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.
Search native plant database:
Vick, Albert F. W.
Rhododendron viscosum (L.) Torr.
Swamp azalea, Clammy azalea, Cory azalea
Synonym(s): Azalea serrulata, Azalea viscosa, Rhododendron coryi, Rhododendron serrulatum, Rhododendron viscosum var. aemulans, Rhododendron viscosum var. glaucum, Rhododendron viscosum var. montanum, Rhododendron viscosum var. nitidum, Rhododendron viscosum var. serrulatum, Rhododendron viscosum var. tomentosum
USDA Symbol: RHVI2
USDA Native Status: L48 (N)
Clammy azalea is a loose, open, deciduous shrub growing to 12 ft. in width, but averaging only about 5 ft. tall. The leaves, clustered at the end of branches, are 1 1/2–3 1/2 inches long and 5/8–1 1/2 inches wide, deciduous, lustrous, green on both sides, with short stems. The sweet-scented flowers are white, with a lavender tube slightly enlarged at the base, 1 1/4–1 3/4 inches long with 5 narrow, petal-like spreading lobes. The 5 stamens are extended. Fall foliage is orange to maroon.
This typical wetland shrub is sometimes called the Clammy Azalea because of its very sticky corolla. The species name means sticky in Latin. The flowers appear after the leaves. Another white wetland species of more southern distribution, the Smooth Azalea (R. arborescens), has smooth twigs, leaves without hairs, and red stamens. Dwarf Azalea (R. atlanticum), with white or pink fragrant flowers on a shrub 3-4 (90-120 cm) tall, is common in deep and along the coastal plain from southern New Jersey to South Carolina.
Plant CharacteristicsDuration: Perennial Habit: Shrub Leaf Retention: Deciduous Leaf Arrangement: Alternate Leaf Complexity: Simple Breeding System:
Flowers Bisexual Size Notes:
Growing up to 15 feet tall but typically around 5 feet. Leaf:
Green Autumn Foliage:
Brown Size Class:
Bloom InformationBloom Color: White , Pink
Bloom Time: May , Jun , Jul , Aug
, VT Native Distribution: ME
s. to FL
& LA Native Habitat:
Swamps; bogs; stream margins
Growing ConditionsWater Use: High
Light Requirement: Part Shade
Soil Moisture: Wet
Soil pH: Acidic (pH<6.8)
CaCO3 Tolerance: Low
Soil Description: Wet soil.
Conditions Comments: This is one of the last azaleas to bloom in spring. It is a variable species with several varieties and forms. Good cultural practices reduce the incidence of disease and insect damage. Flood tolerant.
BenefitUse Wildlife: Low.
Warning: Rhododendrons contain poisonous substances and should not be ingested by humans or animals. Honey made from flowers also may be toxic. POISONOUS PARTS: All parts. Highly Toxic, May be Fatal if eaten. Symptoms include salivation, watering of eyes and nose, abdominal pain, loss of energy, depression, nausea and vomiting, diarrhea, weakness, difficult breathing, progressive paralysis of arms and legs, coma. Toxic Principle: Andromedotoxin. (Poisonous Plants of N.C.)
Conspicuous Flowers: yes
Fragrant Flowers: yes
PropagationDescription: Combine seeds loosely with sphagnum moss and sprinkle lightly over a 2:1 perlite/peat mixture. Germinate under mist or a plastic tent. Optimum temperatures for germination are 45-50 degrees. Transplant seedlings to acid soil with a high content of orga
Seed Treatment: No pretreatment is necessary.
Commercially Avail: yes
Mr. Smarty Plants says
Native shrub to replace non-native azaleas.
February 10, 2009
I want to replace my two dozen azaleas this spring (I think they're unattractive once the flowers fall off). I like the multiseason characteristics of weigela (midnight wine, W&R), but want to go na...
view the full question and answer
National Wetland Indicator Status
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1
(Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here
for map of regions.
From the National Organizations Directory
According to the species list provided by Affiliate Organizations, this plant is either on display or available from the following:
Delaware Nature Society
- Hockessin, DEMt. Cuba Center
- Hockessin, DE
Record Last Modified: 2013-09-08
Research By: TWC Staff