Overview

Comprehensive Description

Distribution

 

USA: Northern West Virginia, south through the mountains of Virginia, North Carolina, Tennessee and Georgia. Generally restricted to the Ridge and Valley Province and Southern Appalachians, with occasional populations in the Cumberland Mountains and in the eastern edge of the Cumberland Plateau in Ohio and Kentucky. Not known west of die Tennessee River Valley in Tennessee. Extending into the Upper Piedmont in North and South Carolina and as far soutii as Meriwether Co., Georgia. Collections from Tarrytown, New York that are R. calendulaceum have been suggested as native in the past (Barnhart, 1895). However, all of the collections are nearly a century old and this is well north of the range of the species. Most likely these were cultivated plants that had persisted.

 
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Royal Botanic Garden Edinburgh

Source: Royal Botanic Garden Edinburgh

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

National Distribution

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Occurrence in North America

     AL  GA  KY  NC  OH  PA  SC  TN  VA  WV

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Flame azalea occurs in the Appalachian Mountains from southern
Pennsylvania and southeastern Ohio south to northern Georgia and
northern Alabama [8,20,28].  Historically it has been reported as far
north as southeastern New York [30].
  • 20.  Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of        the vascular flora of the Carolinas. Chapel Hill, NC: The University of        North Carolina Press. 1183 p.  [7606]
  • 8.  Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of        northeastern United States and adjacent Canada. 2nd ed. New York: New        York Botanical Garden. 910 p.  [20329]
  • 28.  Willingham, F. F., Jr. 1976. Variation and phenological forms in        Rhododendron calendulaceum (Michx.) Torrey (Ericaceae). Castanea. 41(3):        215-223.  [23053]
  • 30.  Young, Stephen M., editor. 1992. New York state rare plant status list.        August 1992. Latham, NY: Department of Environmental Conservation,        Division of Lands and Forests, Natural Heritage Program. 79 p.  [22563]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Description

More info for the terms: capsule, phenology, shrub

Flame azalea is a native, deciduous, erect, much-branched shrub that
grows to 10 feet (3 m) in height.  Its morphology and phenology are
highly variable [28].  The fruit is a capsule [8,20,29].  Rhododendrons
(Rhododendron spp.) have a diffuse shallow root system [22].  Flame
azalea is not rhizomatous [8].
  • 20.  Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of        the vascular flora of the Carolinas. Chapel Hill, NC: The University of        North Carolina Press. 1183 p.  [7606]
  • 8.  Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of        northeastern United States and adjacent Canada. 2nd ed. New York: New        York Botanical Garden. 910 p.  [20329]
  • 22.  Read, D. J. 1983. The biology of mycorrhiza in the Ericales. Canadian        Journal of Botany. 61: 985-1004.  [10602]
  • 28.  Willingham, F. F., Jr. 1976. Variation and phenological forms in        Rhododendron calendulaceum (Michx.) Torrey (Ericaceae). Castanea. 41(3):        215-223.  [23053]
  • 29.  Wofford, B. Eugene. 1989. Guide to the vascular plants of the Blue        Ridge. Athens, GA: The University of Georgia Press. 384 p.  [12908]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Diagnostic Description

 

Shrub or small tree to 10m tall, usually non-rhizomatous; young twigs reddish brown, sparsely to densely covered with unicellular hairs and multicellular eglandular hairs. Vegetative bud scales glabrous abaxially; margin unicellular-ciliate. Leaf blade membranaceous, ovate or obovate to elliptic, (4.5-)5.6-7.7(-9.1) x (1.3-)1.8-2.6(-3.3)cm; base acute to oblique; apex acute to obtuse, often mucronate; adaxial surface sparsely covered with multicellular eglandular and unicellular hairs or with only multicellular eglandular hairs, or glabrous; the midvein densely covered with unicellular hairs; abaxial surface sparsely to densely covered with multicellular eglandular hairs or glabrous; the midvein densely covered with unicellular and multicellular eglandular hairs,rarely densely covered with unicellular hairs and multicellular eglandular hairs, or with only unicellular hairs; margin entire, ciliate with multicellular eglandular hairs; petiole 0.3-0.6(-0.7)cm long, sparsely to densely covered with unicellular hairs and multicellular eglandular hairs. Flower bud scales chestnut brown; abaxial surface glabrous, rarely very sparsely covered with unicellular hairs; margin glandular. Flowers appearing before or as the leaves expand; inflorescence a shortened raceme of 5 to 9 flowers. Pedicels (0.7-)0.8-L2(-1.4)cm long, sparsely to densely covered with unicellular hairs and densely covered with multicellular gland-tipped hairs, or with multicellular eglandular hairs, or both. Sepals (0.1-)0.2-0.3cm long, often varying in length on the same flower; margins glandular-fimbriate, frequently setose; abaxial surface sparsely to densely covered with unicellular hairs and multicellular gland-tipped hairs, rarely with unicellular hairs and multicellular eglandular hairs or with only unicellular hairs. Corolla orange to flame-coloured, fragrance acrid, the tube longer than the limb and abruptly expanding into it; upper corollalobe (1.4-)1.6-2.2(-2.3) x (1.2-)1.5-2.2(-2.5)cm; lateral lobes 1.8-2.6(-3.0) x (0.9-)1.0-1.4(-l .5)cm; corolla tube (1.6-) 1.8-2.2(-2.4)cm long, (0.2-)0.3-0.4(-0.5)cm wide at base; outer surface of corolla sparsely to densely covered with unicellular hairs and densely covered with multicellular gland-tipped hairs which often continue up the corolla lobes; inner surface of corolla sparsely to densely covered with unicellular hairs. Stamens (5.2-)5.7-6.7(-7.2)cm long, with dense terete or flattened unicellular hairs on proximal (1.9-)2.3-3. l(-3.2)cm of filament, exserted (3.4-)3.7-4.8(-5.4)cm beyond throat of corolla. Style (5.5-)5.9~6.8(-7.2)cm long, exserted (3.8-)4.2-5.3(-6.0)cm beyond throat of corolla, with dense unicellular hairs on proximal (0.0-) 0.3-1.3(-1.7)cm; stigma 0.1-0.2(-0.3)cm wide. Ovary 0.3-0.4(-0.5)cm long, (0.1-)0.2-0.3cm wide at the base, densely covered with multicellular eglandular hairs and dense unicellular hairs, rarely with multicellular gland-tipped hairs and unicellular hairs, or with all three types of hairs. Capsules (1.5-)1.8-2.6(-2.9) x (0.5-)0.6-0.8(-0.9)cm, ovate, sparsely covered with unicellular hairs and sparsely to moderately covered with either multicellular eglandular hairs or less often eglandular hairs. Seeds pale to dark chestnut brown, ovate or elliptic to fusiform, (1.7-)2.4-3.9 (-4.2) x (0.6-)0.9-1.5(-1.9)mm, body (0.8-)l.l-1.7(-2.1) x (0.2-)0.4-0.7(-0.8)mm, the testa expanded and dorsiventrally flattened, surrounding the body, the cells elongate, with transverse end-walls.

 
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Royal Botanic Garden Edinburgh

Source: Royal Botanic Garden Edinburgh

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Key Plant Community Associations

More info for the terms: mesic, shrub, shrubs

Flame azalea occurs in mixed deciduous forests [11,19,26].  It occurs in
the well developed shrub layer of oak (Quercus spp.) forests of southern
and western exposures, and with more mesic site species in ravines.
Flame azalea is an important understory shrub in forests formerly
codominated by American chestnut (Castanea dentata) [1,26].

Flame azalea occurs with other ericaceous shrubs including rosebay
rhododendron (Rhododendron maximum), mountain-laurel (Kalmia latifolia),
highbush cranberry (Vaccinium corymbosum), and huckleberry (Gaylussacia
spp.) [1].  It occurs at low coverage in the grassy bald vegetation type
and the grassy bald edge ecotone [26].
  • 1.  Braun, E. L. 1950. Deciduous forests of eastern North America.        Philadelphia, PA: The Blakiston Co. 596 p.  [19637]
  • 11.  Libscomb, M. V.; Nilsen, E. T. 1990. Environmental and physiological        factors influencing the natural distribution of evergreen and deciduous        ericaceous shrubs on ne. and southwest facing slopes of the southern        Appalachian Mountains. II. Water relations. American Journal of Botany.        77(4): 517-526.  [11652]
  • 19.  Quarterman, Elsie; Turner, Barbara Holman; Hemmerly, Thomas E. 1972.        Analysis of virgin mixed mesophytic forests in Savage Gulf, Tennessee.        Bulletin of the Torrey Botanical Club. 99(5): 228-232.  [11128]
  • 26.  Whittaker, R. H. 1956. Vegetation of the Great Smoky Mountains.        Ecological Monographs. 26(1): 1-79.  [11108]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat characteristics

Flame azalea occurs on south- and west-facing slopes of mountainous
sites.  It occurs on submesic to subxeric sites at lower elevations and
on submesic sites at elevations above 5,000 feet (1,500 m) [26].
Adequate humidity and soil moisture are required.  Rhododendrons grow
best on acidic soils from pH 4.5 to 5.5 [4].
  • 4.  Clarke, J. H. 1960. Getting started with rhododendrons and azaleas. New        York: Doubleday & Company, Inc.. 268 p.  [9649]
  • 26.  Whittaker, R. H. 1956. Vegetation of the Great Smoky Mountains.        Ecological Monographs. 26(1): 1-79.  [11108]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat: Ecosystem

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

   FRES13  Loblolly - shortleaf pine
   FRES15  Oak - hickory
   FRES18  Maple - beech - birch

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat: Cover Types

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

    44  Chestnut oak
    52  White oak - black oak - northern red oak
    53  White oak
    55  Northern red oak

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat: Plant Associations

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

   K104  Appalachian oak forest
   K109  Transition between K104 and K106
   K111  Oak - hickory - pine forest

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

 

Found in open, dry sites on southern and western exposures of hills and mountain-sides.

 
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Royal Botanic Garden Edinburgh

Source: Royal Botanic Garden Edinburgh

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

General Ecology

Broad-scale Impacts of Plant Response to Fire

The Research Project Summary Early postfire effects of a prescribed

fire in the southern Appalachians of North Carolina
provides information
on prescribed fire
and postfire response of plant community species,
including flame azalea,
that was not available when this species review
was originally written.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Plant Response to Fire

More info for the term: root crown

Flame azalea probably sprouts from the root crown when top-killed.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Post-fire Regeneration

More info for the term: shrub

   Tall shrub, adventitious-bud root crown

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Fire Ecology

More info for the term: root crown

Flame azalea is probably fire resistant because of its ability to sprout
from the root crown.  Fire may open up maturing forest canopies and
rejuvenate declining flame azalea.  Flame azalea occurs in oak woods
that periodically experience fire [27].
  • 27.  Wilhelm, Gene. 1973. Fire ecology in Shenandoah National Park. In:        Komarek, Edwin V., Sr., technical coordinator. Proceedings, annual Tall        Timbers fire ecology conference; 1972 June 8-9; Lubbock, TX. Number 12.        Tallahassee, FL: Tall Timbers Research Station: 445-488.  [8477]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Regeneration Processes

More info for the term: root crown

Rhododendron fruits split along the sides soon after ripening and
release many small seeds which are disseminated short distances by
wind.  Moist mineral soil or a short moss seedbed is required for
seedling establishment [9,16].

Rhododendrons sprout from the root crown when top-killed [9].

Propagation techniques from cuttings are described [5,23].  Day-night
temperatures and durations for maximizing flame azalea seedling growth
are reported [12].
  • 5.  Doran, William L. 1941. The propagation of some trees and shrubs by        cuttings. Bulletin No. 382. Amherst, MA: Massachusetts State College,        Massachusetts Agricultural Experiment Station. 56 p.  [20255]
  • 9.  Horsley, Stephen B. 1988. How vegetation can influence regeneration. In:        Smith, H. Clay; Perkey, Arlyn W.; Kidd, William E., Jr, eds. Guidelines        for regenerating Appalachian hardwood stands: Workshop proceedings; 1988        May 24-26; Morgantown, WV. Society of American Foresters Publ. 88-03.        Morgantown, WV: West Virginia University Books: 38-54.  [13544]
  • 12.  Malik, A. A.; Blazich, F. A.; Warren, S. L.; Shelton, J. E. 1992.        Initial growth of seedlings of flame azalea in response to day/night        temperature. Journal of the American Society of Horticultural Science.        117(2): 216-219.  [23050]
  • 16.  Olson, David F., Jr. 1974. Rhododendron L.  rhododendron. In:        Schopmeyer, C. S., ed. Seeds of woody plants in the United States.        Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture,        Forest Service: 709-712.  [7739]
  • 23.  Sanders, C. R. 1978. Some aspects of the propagation of Rhododendron,        Mahonia, and Ilex by cuttings. Combined Proceedings, International Plant        Propagators Society. 28: 228-232.  [10693]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Growth Form (according to Raunkiær Life-form classification)

More info on this topic.

More info for the term: phanerophyte

  
   Phanerophyte

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Form

More info for the term: shrub

Shrub

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Successional Status

More info on this topic.

Facultative Seral Species

Flame azalea is intermediate in shade tolerance.  It grows well in the
indirect light of open woods but declines as forests mature and canopies
close [13].
  • 13.  McCance, R. M., Jr.; Burns, J. F., eds. 1984. Ohio endangered and        threatened vascular plants: Abstracts of state-listed taxa. Columbus,        OH: Department of Natural Resources, Division of Natural Areas and        Preserves. 635 p.  [22520]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Cyclicity

Phenology

More info on this topic.

Flame azalea flowers in late April and May at lower elevations and in
June and early July at higher elevations [28].  Flowers appear before or
with the leaves and last several weeks.  Fruit matures July through
September [2,8,20,29].
  • 20.  Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of        the vascular flora of the Carolinas. Chapel Hill, NC: The University of        North Carolina Press. 1183 p.  [7606]
  • 2.  Braun, E. Lucy. 1961. The woody plants of Ohio. Columbus, OH: Ohio State        University Press. 362 p.  [12914]
  • 8.  Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of        northeastern United States and adjacent Canada. 2nd ed. New York: New        York Botanical Garden. 910 p.  [20329]
  • 28.  Willingham, F. F., Jr. 1976. Variation and phenological forms in        Rhododendron calendulaceum (Michx.) Torrey (Ericaceae). Castanea. 41(3):        215-223.  [23053]
  • 29.  Wofford, B. Eugene. 1989. Guide to the vascular plants of the Blue        Ridge. Athens, GA: The University of Georgia Press. 384 p.  [12908]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Barcode data: Rhododendron calendulaceum

The following is a representative barcode sequence, the centroid of all available sequences for this species.


Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Statistics of barcoding coverage: Rhododendron calendulaceum

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

National NatureServe Conservation Status

United States

Rounded National Status Rank: N5 - Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

The status of flame azalea in New York and Maryland is undetermined.
Although historically reported in these states, no extant populations
are known [3,30]. Flame azalea is listed as endangered in Ohio [13].
It is secure throughout the rest of its range.
  • 3.  Broome, C. Rose; Reveal, James L.; Tucker, Arthur O.; Dill, Norman H.        1979. Rare and endangered vascular plants of Maryland. Newton Corner,        MA: U.S. Fish and Wildlife Service. 64 p.  [16508]
  • 13.  McCance, R. M., Jr.; Burns, J. F., eds. 1984. Ohio endangered and        threatened vascular plants: Abstracts of state-listed taxa. Columbus,        OH: Department of Natural Resources, Division of Natural Areas and        Preserves. 635 p.  [22520]
  • 30.  Young, Stephen M., editor. 1992. New York state rare plant status list.        August 1992. Latham, NY: Department of Environmental Conservation,        Division of Lands and Forests, Natural Heritage Program. 79 p.  [22563]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Management considerations

Many nursery cultivars have been developed from flame azalea.  It is
highly sought after for its striking colors and relative cold hardiness
[17,18].  In states where flame azalea is rare, illegal collection is a
threat [13].
  • 13.  McCance, R. M., Jr.; Burns, J. F., eds. 1984. Ohio endangered and        threatened vascular plants: Abstracts of state-listed taxa. Columbus,        OH: Department of Natural Resources, Division of Natural Areas and        Preserves. 635 p.  [22520]
  • 17.  Pellett, N.; Halvorsen, L. 1981. The search for hardy azaleas        Rhododendron calendulaceum, Mt. Pisgah in North Carolina. American        Nurseryman. 153(11): 7, 107.  [23051]
  • 18.  Pellett, N. E.; Rowan, N.; Aleong, J. 1991. Cold hardiness of various        provenances of flame, roseshell, and swamp azaleas. Journal of the        American Society of Horticultural Science. 116(1): 23-26.  [23052]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Other uses and values

More info for the term: shrubs

Flame azalea is considered one of the finest ornamental shrubs in the
United States [14].
  • 14.  McGinnies, William G. 1972. North America. In: McKell, Cyrus M.;        Blaisdell, James P.; Goodin, Joe R., tech. eds. Wildland shrubs--their        biology and utilization: An international symposium: Proceedings; 1971        July; Logan, UT. Gen. Tech. Rep. INT-1. Ogden, UT: U.S. Department of        Agriculture, Forest Service, Intermountain Forest and Range Experiment        Station: 55-66.  [22750]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Rhododendron calendulaceum

Rhododendron calendulaceum (Flame Azalea), is a species of Rhododendron native to the Appalachian Mountains in the eastern United States, ranging from southern New York to northern Georgia.

It is a deciduous shrub, 120–450 cm tall. The leaves are 3–7 cm long, slightly dull green above and villous below. The flowers are 4–5 cm long, usually bright orange, but can vary from pastel orange to dark reddish-orange.

References[edit]

See also[edit]


Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Names and Taxonomy

Taxonomy

The currently accepted scientific name for flame azalea is Rhododendron
calendulaceum (Michx.) Torr. (Ericaceae) [8,20]. There are no currently
accepted infrataxa.
  • 20.  Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of        the vascular flora of the Carolinas. Chapel Hill, NC: The University of        North Carolina Press. 1183 p.  [7606]
  • 8.  Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of        northeastern United States and adjacent Canada. 2nd ed. New York: New        York Botanical Garden. 910 p.  [20329]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Common Names

flame azalea

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Synonyms

Azalea calendulacea Michx. [8,20]
  • 20.  Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of        the vascular flora of the Carolinas. Chapel Hill, NC: The University of        North Carolina Press. 1183 p.  [7606]
  • 8.  Gleason, Henry A.; Cronquist, Arthur. 1991. Manual of vascular plants of        northeastern United States and adjacent Canada. 2nd ed. New York: New        York Botanical Garden. 910 p.  [20329]

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!