''Rhododendron luteum'', the yellow azalea or honeysuckle azalea, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the heath

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

to southeastern Europe and southwest Asia. In Europe, it occurs from southern Poland and Austria, south through the

Balkans The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...

, and east to southern Russia; and in Asia, east to the

Caucasus The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...

. It is a

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

growing . The leaves are

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

, 5–10 cm long and 2–4 cm broad. The flowers are 3–4 cm in diameter, bright yellow, and strongly perfumed, produced in trusses of 5–25 together. The fruit is a dry capsule 15–25 mm long, containing numerous small seeds. The

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...

, containing the neurotoxin

grayanotoxin Grayanotoxins are a group of closely related neurotoxins named after ''Leucothoe grayana'', a plant native to Japan and named for 19th-century American botanist Asa Gray. Grayanotoxin I (grayanotoxane-3,5,6,10,14,16-hexol 14-acetate) is also known ...

; records of

poisoning Poisoning is the harmful effect which occurs when Toxicity, toxic substances are introduced into the body. The term "poisoning" is a derivative of poison, a term describing any chemical substance that may harm or kill a living organism upon ...

of people eating the honey date to the 4th century BC in

Classical Greece Classical Greece was a period of around 200 years (the 5th and 4th centuries BC) in ancient Greece,The "Classical Age" is "the modern designation of the period from about 500 B.C. to the death of Alexander the Great in 323 B.C." ( Thomas R. Mar ...

Cultivation and uses

It is widely cultivated in western Europe, used both as an

ornamental plant Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

in its own right, and as a

rootstock A rootstock is part of a plant, often an underground part, from which new above-ground growth can be produced. It could also be described as a stem with a well developed root system, to which a bud from another plant is grafted. It can refer to ...

onto which other

azalea Azaleas ( ) are flowering shrubs in the genus ''Rhododendron'', particularly the former sections ''Rhododendron sect. Tsutsusi, Tsutsusi'' (evergreen) and ''Pentanthera'' (deciduous). Azaleas bloom in the spring (April and May in the temperate ...

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s are

grafted Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...

. It is locally

naturalised Naturalization (or naturalisation) is the legal act or process by which a non-national of a country acquires the nationality of that country after birth. The definition of naturalization by the International Organization for Migration of the ...

in western and northern Europe. In Great Britain it has colonised many wet

heaths A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...

and

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and musk ...

s, but unlike its relative ''

Rhododendron ponticum ''Rhododendron ponticum'', called common rhododendron or pontic rhododendron, is a species of flowering plant in the ''Rhododendron'' genus of the heath family Ericaceae. It is native to the Iberian Peninsula in southwest Europe and the Caucasus ...

'' it does not usually form dominant stands and so is of lower nature conservation concern. However it is listed under Schedule 9 of the UK

Wildlife and Countryside Act 1981 The Wildlife and Countryside Act 1981 (c. 69) is an act of Parliament in the United Kingdom implemented to comply with European Council Directive 79/409/EEC on the conservation of wild birds. In short, the act gives protection to native species ...

as a non-native invasive species. While it is legal to sell and grow it in gardens, users are expected to take care when disposing of material from this plant. ''R. luteum'' has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

Cultural references

The plant is depicted in place of the crown above the

coat of arms A coat of arms is a heraldry, heraldic communication design, visual design on an escutcheon (heraldry), escutcheon (i.e., shield), surcoat, or tabard (the last two being outer garments), originating in Europe. The coat of arms on an escutcheon f ...

of the Local Community of Boštanj, Slovenia. It was chosen because the area is one of the few habitats of ''Rhododendron luteum'' in

Slovenia Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...

. The coat of arms was created in 1998, during the break-up of the former

Yugoslavia , common_name = Yugoslavia , life_span = 1918–19921941–1945: World War II in Yugoslavia#Axis invasion and dismemberment of Yugoslavia, Axis occupation , p1 = Kingdom of SerbiaSerbia , flag_p ...

Gallery

Sarı çiçekli ormangülü-1.jpg Rhododendron luteum i Oslo.jpg, Fruit Rhododendron luteum BotGardBln1105Autumn.JPG, Autumn foliage Hachmann Rhod Goldtopas.jpg, Cultivar 'Goldtopas' Natural vegetation of Rhododendron luteum 04.jpg, ''Rhododendron luteum'' in the wild

References

Flora Europaea: ''Rhododendron luteum''
*
Plants for a Future: ''Rhododendron luteum''
{{Taxonbar, from=Q2591210 luteum Flora of Armenia Flora of Austria Flora of Azerbaijan Flora of Belarus Flora of Georgia (country) Flora of Greece Flora of Italy Flora of Moldova Flora of Poland Flora of Russia Flora of Slovenia Flora of Turkey Flora of Ukraine