Rhododendron groenlandicum
FAMILY: Ericaceae
SYNONYMS: Ledum, Labrador tea, marsh tea, swamp tea, bog Labrador tea, rusty Labrador tea, Hudson’s Bay tea (formerly Ledum groenlandicum).
GENERAL DESCRIPTION: This beautiful, hardy plant is a shrub belonging to the heather family, which can reach one metre in height. It is recognizable by its thick, leathery evergreen leaves whose edges coil under and are quite unique, being deep green on top with a downy-fuzz beneath. New leaves have a woolly mat of white hairs underneath; mature leaves have reddish hairs. All leaves are dotted with resinous glands and are fragrant, with a pungent scent, when crushed. The fluffy white flowers, which are borne in spring, are also strongly aromatic.
DISTRIBUTION: The plant is native to North America, from Greenland and Labrador across to Alaska, as far north as the treeline. It is absent from the far North and the dry prairies. The Latin name groenlandicum refers to the fact that it grows in Greenland where it is still widespread, often growing in dense colonies.
OTHER SPECIES: Ledum is a genus name, which includes 8 species of evergreen shrubs native to cool temperate and sub-arctic regions of the Northern Hemisphere, commonly known as Labrador tea. The common name Ledum is also applied to Rhododendron tomentsum subsp. subarcticum (formerly L. decumbens) which is known as Northern Labrador tea. This species, which is similar but slightly smaller, grows farther north on tundra at up to 1,800 metres and contains toxic alkaloids known to be poisonous to livestock. It lacks the characteristic fuzz on the underside of the mature leaves and the flowers of L. groenlandicum.
HERBAL/FOLK TRADITION: This strongly aromatic herb has been used in folk medicine for centuries. Brewed as a medicinal beverage known as Labrador tea, it was used by practically all Canada’s First Nations peoples as a tonic and to treat certain respiratory, digestive and kidney ailments; as a remedy for headaches and various types of rheumatism; and to facilitate childbirth. The herbal tea also served to clean wounds and was applied to insect bites. It is said that the plant was used for over 5,000 years by the native people of North America, to protect themselves from scurvy, and the Cree used it for fevers and colds: indeed it was regarded as a ‘cure-all’ by the indigenous people. In the fur-trading era, the French Canadian coureurs-de-bois used Labrador tea to extend their supplies of black tea: it thus became a substitute for unaffordable Chinese tea during times of economic crisis. However, like other plants in the heather family, Greenland moss contains an andromedo-toxin that can cause poisoning if used in excess.
According to recent clinical trials, Greenland moss essential oil has a natural affinity for the immune system and can be an effective immune system supporter. The oil also helps counteract blood toxicity and aids liver regeneration, valuable in cases of liver intoxication originating from circulation disorders, viral hepatitis, enteritis and cirrhosis (fatty liver). Clinical research suggests that the essential oil functions like an enzyme in the liver, digesting toxic waste and fat molecules. It is also indicated for obesity, oedema, water retention and thyroid regulation. The oil has also been studied at the University of Quebec, and was found to be a strong antioxidant and natural anti-inflammatory: it also showed anticancer activity against colon carcinoma and lung carcinoma cells.
ACTIONS: Analgesic, antibacterial, anticancerous, antiviral, anti-inflammatory, anti-tumoral, antispasmodic, antioxidant, anti-infectious, antiseptic, carminative, cicatrizing, decongestant, digestive tonic, immune support, liver support, stomachic, tonic.
EXTRACTION: Greenland moss oil is extracted by steam distillation from the leaves.
CHARACTERISTICS: A clear, pale-yellow liquid, with a fresh-herbaceous, medicinal and slightly sweet aroma and earthy-woody undertones.
PRINCIPAL CONSTITUENTS: The main chemical constituents are limonene (up to 35 per cent), sabinene, selinene, bornyl acetate with other monoterpenes and sesquiterpenes.
SAFETY DATA: Possible skin sensitization: always dilute for topical use. Avoid during pregnancy and by children. NB: Abusive consumption of the tea derived from its leaves may cause indigestion, and may even have a toxic effect due to the high level of tannins that it contains.
AROMATHERAPY/HOME: USE
Skin Care: Allergies, skin problems.
Circulation Muscles And Joints: Aching muscles and joints.
Respiratory System: Colds, coughs, bronchitis, hoarseness, influenza, laryngitis.
Digestive System: Addictions, alcoholism, allergies, cellulite, fatty liver, hepatitis (viral), hypothyroid, liver problems (toxic liver, support and detoxifier), lymph nodes (inflamed), obesity, thyroid regulation and water retention.
Immune System: Tonic and immune support.
Nervous System: Anxiety, nervous debility tension.
OTHER USES: The plant is still used as a local ‘tea plant’ in parts of the Northern Hemisphere.... greenland moss