View source for Rhododendron calendulaceum

{{Treatment/ID
|accepted_name=Rhododendron calendulaceum
|accepted_authority=(Michaux) Torrey
|publications={{Treatment/Publication
|title=Fl. N. Middle United States,
|place=425. 1824 ,
}}
|common_names=Flame azalea
|basionyms={{Treatment/ID/Basionym
|name=Azalea calendulacea
|authority=Michaux
|rank=species
|publication_title=Fl. Bor.-Amer.
|publication_place=1: 151. 1803
}}
|synonyms=
|hierarchy=Ericaceae;Ericaceae subfam. Ericoideae;Rhododendron;Rhododendron calendulaceum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Ericaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Ericaceae subfam. Ericoideae]]</div><div class="higher-taxon"><small>genus</small>[[Rhododendron]]</div><div class="higher-taxon"><small>species</small>[[Rhododendron calendulaceum]]</div></div>
|volume=Volume 8
|mention_page=page 458, 466, 469, 470, 471
|treatment_page=page 465
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Shrubs </b>or trees, to 4(–10) m, usually not rhizomatous. <b>Stems</b>: bark smooth to vertically furrowed, shredding; twigs sparsely to conspicuously multicellular eglandular-hairy (hairs unbranched), otherwise sparsely to moderately unicellular-hairy. <b>Leaves</b> deciduous; petiole multicellular eglandular-hairy and unicellular-hairy; blade ovate to obovate, 4.5–9.1 × 1.3–3.3 cm, thin, membranous to chartaceous, margins entire, plane, ciliate, eglandular-hairy, apex acute to obtuse, often mucronate, abaxial surface glabrous or densely eglandular-hairy, often also very sparsely to moderately unicellular-hairy, adaxial surface glabrous or sparsely scattered eglandular-hairy, often also sparsely unicellular-hairy. <b>Floral</b> bud scales usually glabrous abaxially, margins glandular. <b>Inflorescences</b> 5–9-flowered; bracts similar to bud scales. <b>Pedicels</b> 7–14 mm, stipitate-glandular-hairy and/or eglandular-hairy, otherwise sparsely to densely unicellular-hairy. <b>Flowers</b> opening before or as leaves expand, erect to horizontal, acrid-scented; calyx lobes 1–3 mm, scattered usually stipitate-glandular-hairy and unicellular-hairy, margins long stipitate-glandular-hairy and/or eglandular-hairy; corolla orange to red-orange, with contrasting, darker-colored, orange to yellow blotch on upper lobe, funnelform, 30–54 mm, densely multicellular stipitate-glandular-hairy, otherwise sparsely to densely unicellular-hairy on outer surface, petals connate, lobes 14–30 mm, (spreading nearly as broadly as tube is long), tube abruptly expanding into lobes, 16–28 mm (longer than lobes); stamens 5, much exserted, ± unequal, 52–72 mm. <b>Capsules</b> borne on erect pedicels, 15–29 × 5–9 mm, sparsely to moderately long stipitate-glandular-hairy and/or eglandular-hairy, and sparsely unicellular-hairy. <b>Seeds</b> without distinct tails, flattened portion of testa well developed at each end; testa expanded, dorsiventrally flattened, ± loose. <b>2n</b> = 52.</span><!--

-->{{Treatment/Body
|phenology=Flowering spring–summer.
|habitat=Mixed deciduous forests
|elevation=200-1000 m
|distribution=Ga.;Ky.;Md.;N.C.;Ohio;Pa.;S.C.;Tenn.;Va.;W.Va.
|discussion=<p><i>Rhododendron calendulaceum</i>, frequently confused with the diploid <i>R. cumberlandense</i>, is an allotetraploid, and may have been derived from a hybrid between an ancestor of <i>R. cumberlandense</i> and one of <i>R. prinophyllum</i> (K. A. Kron 1993). It is distinguished from <i>R. cumberlandense</i> by its flowers opening before or with (versus after) the expansion of the leaves, glandular or eglandular (versus usually eglandular) pedicels, glandular or eglandular (versus usually eglandular) sepal margins (<i>R. cumberlandense</i> never with both pedicels and sepal margins glandular), and nonglaucous (versus often glaucous) abaxial leaf surface. <i>Rhododendron calendulaceum</i> is one of the showiest shrubs of the southern Appalachians; it is known to hybridize with <i>R. prinophyllum</i> and <i>R. canescens</i>.</p><!--
--><p><i>Rhododendron calendulaceum</i> and the remaining species (through 25. <i>R. eastmanii</i>) are the North American representatives of sect. Pentanthera G. Don, a group characterized by corollas that are typically unicellular-hairy on the outside and with a narrow tube, flowers with five, declinate, and usually much-exserted stamens, and seeds with ± loose testae (K. A. Kron 1993; Kron and M. Creel 1999). All species are used as ornamentals because of their colorful flowers(F. C. Galle 1985).</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Rhododendron calendulaceum
|authority=(Michaux) Torrey
|rank=species
|parent rank=genus
|synonyms=
|basionyms=Azalea calendulacea
|family=Ericaceae
|phenology=Flowering spring–summer.
|habitat=Mixed deciduous forests
|elevation=200-1000 m
|distribution=Ga.;Ky.;Md.;N.C.;Ohio;Pa.;S.C.;Tenn.;Va.;W.Va.
|reference=None
|publication title=Fl. N. Middle United States,
|publication year=
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V8/V8_910.xml
|subfamily=Ericaceae subfam. Ericoideae
|genus=Rhododendron
|species=Rhododendron calendulaceum
}}<!--

-->[[Category:Treatment]][[Category:Rhododendron]]