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Useful Temperate Plants

Rhododendron groenlandicum

(Oeder) Kron & Judd

Ericaceae

+ Synonyms

Ledum groenlandicum Oeder

Ledum latifolium Jacq.

Common Name: Labrador Tea

No Image.

General Information

Rhododendron groenlandicum is an evergreen shrub with erect and/or prostrate stems growing from a rhizomatous rootstock; it can grow 20 - 150cm tall[
270
Title
Flora of N. America
Publication
 
Author
 
Website
http://flora.huh.harvard.edu/fna/
Publisher
 
Year
0
ISBN
 
Description
An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
].
The plant is often used to make a tea and is often used medicinally. It is harvested from the wild for mainly local use as a food, medicine and source of materials. It is grown as an ornamental in gardens.

Known Hazards

Plants contain a narcotic toxin called Ledol - this is a sesquiterpene that can cause cramps, paralysis, and delirium. Ledol is also said to have various beneficial effects if consumed in the correct dosage and it is said that, when ingested as a herbal tea, it only causes problems if the leaves are cooked for a long period in a closed container[
172
Title
Discovering Wild Plants - Alaska, W. Canada and the Northwest.
Publication
 
Author
Schofield. J. J.
Publisher
Alaska Northwest Books; Alaska
Year
2003
ISBN
0882403699
Description
A nice guide to some useful plants in that area.
].

Botanical References

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.
,
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.
,
270
Title
Flora of N. America
Publication
 
Author
 
Website
http://flora.huh.harvard.edu/fna/
Publisher
 
Year
0
ISBN
 
Description
An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.

Range

Northern N. America - Alaska to Greenland and Newfoundland, south to Oregon, Idaho, Manitoba, Minnesota and Pennsylvania

Habitat

Bogs, spruce forests, muskeg, swamps, stream margins, talus slopes, tundra; at elevations up to 2,000 metres[
270
Title
Flora of N. America
Publication
 
Author
 
Website
http://flora.huh.harvard.edu/fna/
Publisher
 
Year
0
ISBN
 
Description
An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
]. Cold bogs and montane coniferous woods[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
50
Title
Flora Europaea
Publication
 
Author
?
Publisher
Cambridge University Press
Year
1964
ISBN
-
Description
An immense work in 6 volumes (including the index). The standard reference flora for Europe, it is very terse though and with very little extra information. Not for the casual reader.
].

Properties

Edibility Rating *  *
Medicinal Rating *  *  *
Other Uses Rating *  *
HabitEvergreen Shrub
Height1.50 m
PollinatorsBees
Cultivation StatusOrnamental, Wild

Cultivation Details

Rhododendron groenlandicum is hardy to at least -15°c[
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.
]. 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.
].
Requires a lime-free loam or peaty soil[
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]).
,
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.
]. Prefers a moist humus-rich acid soil in shade or semi-shade[
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.
]. Plants flower more freely when grown in a sunny position. Plants grow better if they have certain fungal associations in the soil. The best way of providing this is to incorporate some soil from around well-growing established plants into the soil for the new plant[
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.
].
The leaves and the flowers are very aromatic[
182
Title
Ornamental Shrubs, Climbers and Bamboos.
Publication
 
Author
Thomas. G. S.
Publisher
Murray
Year
1992
ISBN
0-7195-5043-2
Description
Contains a wide range of plants with a brief description, mainly of their ornamental value but also usually of cultivation details and varieties.
,
245
Title
Scented Flora of the World.
Publication
 
Author
Genders. R.
Publisher
Robert Hale. London.
Year
1994
ISBN
0-7090-5440-8
Description
An excellent, comprehensive book on scented plants giving a few other plant uses and brief cultivation details. There are no illustrations.
].
Plants benefit from removing the dead flowers before they set seed[
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.
]. This prevents them putting too much energy into seed production at the expense of more flowers and leaves.
This species is considered by some botanists to be no more than a sub-species of Rhododendron tomentosum[
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.
,
50
Title
Flora Europaea
Publication
 
Author
?
Publisher
Cambridge University Press
Year
1964
ISBN
-
Description
An immense work in 6 volumes (including the index). The standard reference flora for Europe, it is very terse though and with very little extra information. Not for the casual reader.
].
A good bee plant[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
].

Edible Uses

Some caution is advised if consuming this plant - see the notes above on toxicity.

A fragrant and soothing tea is made from the leaves[
2
Title
Sturtevant's Edible Plants of the World.
Publication
 
Author
Hedrick. U. P.
Publisher
Dover Publications
Year
1972
ISBN
0-486-20459-6
Description
Lots of entries, quite a lot of information in most entries and references.
,
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
95
Title
Edible and Useful Wild Plants of the United States and Canada.
Publication
 
Author
Saunders. C. F.
Publisher
Dover Publications
Year
1976
ISBN
0-486-23310-3
Description
Useful wild plants of America. A pocket guide.
,
102
Title
Native Harvests.
Publication
 
Author
Kavasch. B.
Publisher
Vintage Books
Year
1979
ISBN
0-394-72811-4
Description
Another guide to the wild foods of America.
,
172
Title
Discovering Wild Plants - Alaska, W. Canada and the Northwest.
Publication
 
Author
Schofield. J. J.
Publisher
Alaska Northwest Books; Alaska
Year
2003
ISBN
0882403699
Description
A nice guide to some useful plants in that area.
]. The spicy leaves make a very palatable and refreshing tea[
183
Title
Cornucopia - A Source Book of Edible Plants.
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications
Year
1990
ISBN
0-9628087-0-9
Description
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
]. The North American Indians would often flavour this tea with the roots of liquorice fern, Polypodium glycyrrhiza[
256
Title
Food Plants of Coastal First Peoples
Publication
 
Author
Turner. N. J.
Publisher
UBC Press. Vancouver.
Year
1995
ISBN
0-7748-0533-1
Description
Excellent little handbook about the native food plants of Western Canada. Good descriptions of the plants and their uses with colour photos of most plants.
]. When lemon is added they can be used as iced tea[
183
Title
Cornucopia - A Source Book of Edible Plants.
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications
Year
1990
ISBN
0-9628087-0-9
Description
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
]. The leaves were once added to beer in order to make it heady[
183
Title
Cornucopia - A Source Book of Edible Plants.
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications
Year
1990
ISBN
0-9628087-0-9
Description
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
].
Some caution is advised, see the notes above on toxicity. It would be better to brew the tea in cold water by leaving it in a sunny place, or to make sure that it is brewed for a short time only in an open container.

The leaves are used as a flavouring, they are a bayleaf substitute[
172
Title
Discovering Wild Plants - Alaska, W. Canada and the Northwest.
Publication
 
Author
Schofield. J. J.
Publisher
Alaska Northwest Books; Alaska
Year
2003
ISBN
0882403699
Description
A nice guide to some useful plants in that area.
].

Medicinal

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

Labrador tea was employed medicinally by several native North American Indian tribes who used it to treat a variety of complaints[
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
]. In modern herbalism it is occasionally used externally to treat a range of skin problems.

The leaves are analgesic, blood purifier, diaphoretic, diuretic, pectoral and tonic[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
172
Title
Discovering Wild Plants - Alaska, W. Canada and the Northwest.
Publication
 
Author
Schofield. J. J.
Publisher
Alaska Northwest Books; Alaska
Year
2003
ISBN
0882403699
Description
A nice guide to some useful plants in that area.
,
222
Title
A Field Guide to Medicinal Plants. Eastern and Central N. America.
Publication
 
Author
Foster. S. & Duke. J. A.
Publisher
Houghton Mifflin Co.
Year
1990
ISBN
0-395-46722-5
Description
A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
,
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
]. A tea is taken internally in the treatment of headaches, asthma, colds, stomach aches, kidney ailments etc[
222
Title
A Field Guide to Medicinal Plants. Eastern and Central N. America.
Publication
 
Author
Foster. S. & Duke. J. A.
Publisher
Houghton Mifflin Co.
Year
1990
ISBN
0-395-46722-5
Description
A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
,
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
].
Externally, it is used as a wash for burns, ulcers, itches, chapped skin, stings, dandruff etc[
222
Title
A Field Guide to Medicinal Plants. Eastern and Central N. America.
Publication
 
Author
Foster. S. & Duke. J. A.
Publisher
Houghton Mifflin Co.
Year
1990
ISBN
0-395-46722-5
Description
A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
,
238
Title
Encyclopaedia of Herbs and their Uses.
Publication
 
Author
Bown. D.
Publisher
Dorling Kindersley, London.
Year
1995
ISBN
0-7513-020-31
Description
A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
,
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
]. An ointment made from the powdered leaves or roots has been used to treat ulcers, cracked nipples, burns and scalds[
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
].

An essential oil obtained from the plant is used in aromatherapy[
277
Title
Plants Database
Publication
 
Author
 
Website
http://plants.usda.gov/java/factSheet
Publisher
United States Department of Agriculture
Year
0
ISBN
 
Description
An online database with an excellent collection of fact sheets about native N. American plants.
].

The plant is apparently a mild narcotic, it was taken by Indian women three times daily shortly before giving birth[
207
Title
The History and Folklore of North American Wild Flowers.
Publication
 
Author
Coffey. T.
Publisher
Facts on File.
Year
1993
ISBN
0-8160-2624-6
Description
A nice read, lots of information on plant uses.
]

Studies have shown that a methanol extract of the leaves and twigs has significant anti-inflammatory and antioxidant activities[
277
Title
Plants Database
Publication
 
Author
 
Website
http://plants.usda.gov/java/factSheet
Publisher
United States Department of Agriculture
Year
0
ISBN
 
Description
An online database with an excellent collection of fact sheets about native N. American plants.
].
A water extract (tea) of the twigs has been shown to be active against lung and colon carcinoma cell lines[
277
Title
Plants Database
Publication
 
Author
 
Website
http://plants.usda.gov/java/factSheet
Publisher
United States Department of Agriculture
Year
0
ISBN
 
Description
An online database with an excellent collection of fact sheets about native N. American plants.
].

Other Uses

The leaves are hung up in the clothes cupboard in order to repel insects[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
]. The branches are also placed among grain in order to keep mice away[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
]. A strong decoction of the leaves, or a tincture, is used to kill lice, mosquitoes, fleas and other insects[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
207
Title
The History and Folklore of North American Wild Flowers.
Publication
 
Author
Coffey. T.
Publisher
Facts on File.
Year
1993
ISBN
0-8160-2624-6
Description
A nice read, lots of information on plant uses.
,
238
Title
Encyclopaedia of Herbs and their Uses.
Publication
 
Author
Bown. D.
Publisher
Dorling Kindersley, London.
Year
1995
ISBN
0-7513-020-31
Description
A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
].

The leaves contain tannin[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
].

A brown dye is obtained from the plant[
257
Title
Native American Ethnobotany
Publication
 
Author
Moerman. D.
Publisher
Timber Press. Oregon.
Year
1998
ISBN
0-88192-453-9
Description
Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
].

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. 2024-03-28. <temperate.theferns.info/plant/Rhododendron+groenlandicum>

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