If you would like to support this site, please consider Donating.
Useful Temperate Plants

Rhododendron hirsutum

L.

Ericaceae

+ Synonyms

Azalea hirsuta (L.) Kuntze

Chamaerhododendron hirsutum (L.) Bubani

Common Name: Hairy Alpenrose

No Image.

General Information

Rhododendron hirsutum is a dwarf, evergreen shrub of close habit - it can eventually reach up to 100cm tall and wide, forming a dense hemispherical mass[
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
].
The plant is harvested from the wild for local use as a medicine. It is grown as an ornamental in gardens, being valued as one of the few speecies in this genus that can succeed in a calcareous soil[
338
Title
IUCN Red List of Threatened Species
Publication
 
Author
 
Website
http://www.iucnredlist.org/
Publisher
 
Year
0
ISBN
 
Description
A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
].
Rhododendron hirsutum is an abundant species in montane areas of the Alps; it has a relatively broad distribution, stable populations and no major threats. It has, however, declined in Croatia where it was collected from the wild for medicinal value, but it is now a protected species there. Globally, the plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[
338
Title
IUCN Red List of Threatened Species
Publication
 
Author
 
Website
http://www.iucnredlist.org/
Publisher
 
Year
0
ISBN
 
Description
A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
].

Known Hazards

Although no specific mention of toxicity has been seen for this species, all parts of Rhododendron species (including the leaves, flowers and pollen) contain greater or lesser amounts of the toxic compound andromedotoxin (also known as grayanotoxin). Rarely lethal to humans (and used medicinally in some herbal disciplines), this compound causes dose-dependant overstimulation of the central nervous system with symptoms including various cardiovascular effects (mainly low blood pressure and cardiac rhythm disorders); nausea and vomiting; and a change in consciousness. The effects commence shortly after ingestion and last around two days. These effects are also transferred to honey made from the nectar of the flowers. In some parts of the world bees are used to deliberately produce a honey rich in andromedotoxin which is then eaten for its supposed medicinal, hallucinogenic and aphrodisiac effects.
In contrast to humans, many other creatures are more susceptible to the toxin and it has sometimes proved lethal to grazing animals and household pets. Some forms of honeybees are also killed by the toxin (resistant forms of the bee are used for honey production). Bumblebees are not affected, however, and are also more efficient in pollinating rhododendron flowers, so one theory is that the toxin is produced by the plant in order to favour the bumblebee and improve fertilization rates[
1668
Title
Grayanotoxin Poisoning: ‘Mad Honey Disease’ and Beyond
Publication
Cardiovasc Toxicol (2012) 12:208-215
Author
Jansen S.A. et al
Website
https://doi.org/10.1007/s12012-012-9162-2
Publisher
 
Year
2012
ISBN
 
Description
An in-depth review of the literature on the toxic effects of a toxin widely found in the family Ericaceae
].

Botanical References

200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.

Range

Europe - mountainous areas from France to Germany, south to Italy and Croatia

Habitat

Dry, open, stony soils and screes, growing in dwarf shrub heath and herb rich grassland above the tree line, preferring calcareous soils; at elevations up to 2,500 metres[
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
,
338
Title
IUCN Red List of Threatened Species
Publication
 
Author
 
Website
http://www.iucnredlist.org/
Publisher
 
Year
0
ISBN
 
Description
A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
].

Properties

Conservation StatusLeast Concern
Medicinal Rating *  *
HabitEvergreen Shrub
Height1.00 m
Growth RateSlow
Cultivation StatusOrnamental, Wild

Cultivation Details

Rhododendron hirsutum is a very cold-tolerant plant, when fully dormant it can withstand temperatures down to about -30°c. Although cold-tolerant when dormant, the flowers and young growth of Rhododendrons are very susceptible to damage by late frosts in regions where these are likely to occur after new growth has commenced in the spring[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Rhododendron species generally succeed when grown in a non-compacted, humus rich lime free soil and a position with some shade, preferably light woodland shade. They strongly dislike soils of a dry arid nature, heavy soils or clays[
1
Title
RHS Dictionary of Plants plus Supplement. 1956
Publication
 
Author
F. Chittendon.
Publisher
Oxford University Press
Year
1951
ISBN
-
Description
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
]. Prefers a peaty or well-drained sandy loam[
1
Title
RHS Dictionary of Plants plus Supplement. 1956
Publication
 
Author
F. Chittendon.
Publisher
Oxford University Press
Year
1951
ISBN
-
Description
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
]. Succeeds in sun or shade, the warmer the climate the more shade a plant requires[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Requires a pH between 4.5 and 5.5[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Rhododendron species are mainly woodland species that grow well in the dappled shade and shelter given by the other woodland plants. They are surface-rooting species with a fibrous root system, however, and do not grow well close to trees that are also surface-rooting, nor do they do well with ground cover or other small plants growing over or into their roots[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
,
352
Title
KemperCentreForHomeGardeningPlantFinder
Publication
 
Author
 
Website
http://www.mobot.org/gardeninghelp/plantfinder/
Publisher
Missouri Botanical Garden
Year
0
ISBN
 
Description
Basic cultivation details, plant uses, habitat etc for several thousand species of plants, mainly from the temperate zone.
].
Plants form a root ball and are very tolerant of being transplanted, even when quite large, so long as the root ball is kept intact[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].

Edible Uses

None known

Medicinal

Some caution is advised in the medicinal usage of this plant - see the notes above on toxicity.

Used as a medicinal and aromatic plant for the treatment of inflammation, pain, skin ailments, common cold and gastro-intestinal disorders[
338
Title
IUCN Red List of Threatened Species
Publication
 
Author
 
Website
http://www.iucnredlist.org/
Publisher
 
Year
0
ISBN
 
Description
A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
].

Other Uses

None known

Propagation

Seed - surface sow in a shady part of the greenhouse in late winter or early spring[
78
Title
Propagation of Trees, Shrubs and Conifers.
Publication
 
Author
Sheat. W. G.
Publisher
MacMillan and Co
Year
1948
ISBN
-
Description
A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
,
113
Title
The Reference Manual of Woody Plant Propagation.
Publication
 
Author
Dirr. M. A. and Heuser. M. W.
Publisher
Athens Ga. Varsity Press
Year
1987
ISBN
0942375009
Description
A very detailed book on propagating trees. Not for the casual reader.
]. Another report says that the seed is best sown in the autumn as soon as it is ripe[
188
Title
The RHS Gardener's Encyclopedia of Plants and Flowers
Publication
 
Author
Brickell. C.
Publisher
Dorling Kindersley Publishers Ltd.
Year
1990
ISBN
0-86318-386-7
Description
Excellent range of photographs, some cultivation details but very little information on plant uses.
]. Germination is variable and can be quite slow. Prick out the seedlings into individual pots as soon as they are large enough to handle and grow the pots on in a shady frame for 18 months before planting them out into their permanent positions[
78
Title
Propagation of Trees, Shrubs and Conifers.
Publication
 
Author
Sheat. W. G.
Publisher
MacMillan and Co
Year
1948
ISBN
-
Description
A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
].
Cuttings of half-ripe wood, 5 - 8cm with a heel, mid summer in a frame. Plant out in spring. Fair percentage[
78
Title
Propagation of Trees, Shrubs and Conifers.
Publication
 
Author
Sheat. W. G.
Publisher
MacMillan and Co
Year
1948
ISBN
-
Description
A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
].
Cuttings of mature wood, late autumn in a frame[
113
Title
The Reference Manual of Woody Plant Propagation.
Publication
 
Author
Dirr. M. A. and Heuser. M. W.
Publisher
Athens Ga. Varsity Press
Year
1987
ISBN
0942375009
Description
A very detailed book on propagating trees. Not for the casual reader.
].
Layering in the autumn. Takes 12 months[
78
Title
Propagation of Trees, Shrubs and Conifers.
Publication
 
Author
Sheat. W. G.
Publisher
MacMillan and Co
Year
1948
ISBN
-
Description
A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
].
Division.
Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2024-03-19. <temperate.theferns.info/plant/Rhododendron+hirsutum>

Add a Comment:

If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.