Home/Species/ Swamp Azalea

Rhododendron viscosum

(L.) Torr.

Swamp Azalea

G5Secure Found in 7 roadless areas NatureServe Explorer →

G5SecureGlobal Rank

UnknownThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.129022

Element CodePDERI150U0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicendemic to a single nation

KingdomPlantae

PhylumAnthophyta

ClassDicotyledoneae

OrderEricales

FamilyEricaceae

GenusRhododendron

Other Common Names

swamp azalea (EN)

Concept Reference

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Conservation Status

Rank Method Rank calculation - Biotics v2

Review Date2023-03-16

Change Date1984-08-29

Edition Date2023-03-16

Edition AuthorsEberly (2023)

Threat ImpactUnknown

Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)

Number of Occurrences> 300

Rank Reasons

Rhododendron viscosum is a deciduous shrub or small tree with attractive flowers that occurs throughout the eastern United States. With a large range extent, over 600 occurrences, and general habitat preferences, this species is considered secure.

Range Extent Comments

Rhododendron viscosum occurs throughout the eastern United States from Maine, New Hampshire, and New York, south to central peninsular Florida and southwest to West Virginia, Tennessee, Arkansas, and eastern Oklahoma and Texas. Range extent was estimated using herbarium specimen, NatureServe Network occurrence data, and photo-based observation data collected between 1992 and 2023 (GBIF 2023, iNaturalist 2023, SEINet 2023). The only occurrences in Vermont are considered non-native.

Occurrences Comments

By applying a 1 km separation distance to herbarium records, NatureServe Network data, and photo-based observations documented between 1992 and 2023, it is estimated that there are over 600 occurrences rangewide (GBIF 2023, iNaturalist 2023, SEINet 2023). Within the southeastern U.S.A., it is most common on the Piedmont, the Coastal Plain of Texas and Louisiana, and the Interior Highlands of Arkansas (Weakley and Southeastern Flora Team 2023).

Threat Impact Comments

The level of threat to this species is unknown. Some potential threats include alterations to the site hydrology and over zealous wild collection or wildflower picking.

Ecology & Habitat

Habitat

This species occurs in a variety of moist habitats including acid swamps, bogs, seepage slopes, pocosins, streambanks, streamheads and baygalls, wet pine flatwoods, moist pine or pine/oak forests, hummocks, shrub balds (Flora of North America Editorial Committee 2009, Weakley and Southeastern Flora Team 2023).

Terrestrial Habitats

Forest/WoodlandForest - HardwoodForest - ConiferForest - MixedShrubland/chaparral

Palustrine Habitats

SCRUB-SHRUB WETLANDFORESTED WETLAND

Other Nations (1)

United StatesN5

Province	Rank	Native
North Carolina	S5	Yes
Massachusetts	SNR	Yes
District of Columbia	SNR	Yes
Delaware	S5	Yes
Vermont	SNA	No
Mississippi	SNR	Yes
South Carolina	SNR	Yes
Alabama	SNR	Yes
Connecticut	SNR	Yes
Tennessee	SNR	Yes
New Hampshire	S3	Yes
New York	S5	Yes
West Virginia	S1	Yes
Texas	SNR	Yes
New Jersey	S5	Yes
Pennsylvania	SNR	Yes
Georgia	SNR	Yes
Maryland	SNR	Yes
Florida	SNR	Yes
Oklahoma	S1	Yes
Louisiana	S5	Yes
Rhode Island	SNR	Yes
Maine	S1	Yes
Arkansas	SNR	Yes
Virginia	S4	Yes

Threat Assessments

Threat	Scope	Severity	Timing
5 - Biological resource use	Unknown	Unknown	High (continuing)
5.1 - Hunting & collecting terrestrial animals	Unknown	Unknown	High (continuing)
5.1.1 - Intentional use (species being assessed is the target)	Unknown	Unknown	High (continuing)
7 - Natural system modifications	Unknown	Unknown	High (continuing)

Plant Characteristics

DurationPERENNIAL, Long-lived, DECIDUOUS, SUMMER-FLOWERING

Economic Value (Genus)No

Roadless Areas (7)

Florida (1)

Area	Forest	Acres
Clear Lake	Apalachicola National Forest	5,592

Georgia (1)

Area	Forest	Acres
Sarah's Creek	Chattahoochee National Forest	6,888

Louisiana (1)

Area	Forest	Acres
Saline Bayou W & S River Corridor	Kisatchie National Forest	5,355

North Carolina (4)

Area	Forest	Acres
Catfish Lake North	Croatan National Forest	11,299
Laurel Mountain	Pisgah National Forest	5,683
Pond Pine B	Croatan National Forest	2,961
Sheep Ridge Addition	Croatan National Forest	5,808

References (6)

Flora of North America Editorial Committee (FNA). 2009. Flora of North America north of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.
Global Biodiversity Information Facility (GBIF). 2023. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2023).
iNaturalist. 2023. Online. Available: https://www.inaturalist.org (accessed 2023).
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
NatureServe. 2023. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
Southwest Environmental Information Network (SEINet). 2023. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2023).

Rhododendron viscosum

Habitat

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