Rhododendron groenlandicum

Description

It is a low shrub growing to 50 cm tall – rarely up to 2 m – with evergreen leaves 2 – long and 3 – broad. The leaves are wrinkled on top with a thick waxy cuticle and have a leathery texture. The underside is covered in dense white hair that turns red-brown with age. The flowers of R. groenlandicum are small, white, and perfect (bisexual). Their hemispherical clusters have up to 35 flowers with petals approximately 1 cm long. With 5 oval shaped petals it produces a sweet aroma and sticky nectar to attract pollinators.

R. groenlandicum is self-compatible; however, self-fertilization results in a lower fruit set and fewer seeds per fruit “than cross-pollination”. Pollination is primarily performed by bees; however, butterflies and beetles can also act as pollinators.

|Loddiges 534 Ledum latifolium drawn by W Miller.jpg|Illustration by William Miller |Labrador Tea (Rhododendron groenlandicum) - Port Rexton, Newfoundland 2019-08-14.jpg|Specimen in Newfoundland and Labrador

Distribution and habitat

It is reported from Greenland, as well as from every province and territory in Canada and in the northern United States including the Northeast (New England, New York, Pennsylvania), the Northwest (Oregon, Washington, Idaho, Alaska), and parts of the Upper Midwest (Michigan, Wisconsin, Minnesota). It grows in bogs, muskegs, and open tundra, as well as occasionally on wet shores and rocky alpine slopes.

Toxicity

The plant contains toxic alkaloids which are poisonous to livestock and may be toxic to humans in concentrated doses.

Harvesting

Due to the plant’s slow growth, tea leaves are collected only from multiple plants in the spring by taking one. Labrador tea is slow-growing, so only a single new leaf is collected from a plant every other year to avoid damaging the plants.

Uses

The leaves are regularly used to make beverages and medicines—most commonly a fragrant tea—by many Native American tribes such as the Quinault and Makah, the Potawatomi, the Anishinaabe, the Iroquois, and First Nations tribes in Canada. Antioxidant, anti-inflammatory and anticancer activity has been found. When European explorers arrived, they soon adopted these uses as well, dubbing it "Indian plant tea". During the American Revolutionary War, it was used as a substitute for tea. It was used as ale flavoring in Europe prior to hops becoming the main flavor/preservative ingredient

Rhododendron groenlandicum is sometimes grown as an ornamental shrub. Its essential oil is also popular in aromatherapy.

References

References

1. "''Rhododendron groenlandicum''".
2. (1990). "Phylogenetic Relationships within the Rhodoreae (Ericaceae) with Specific Comments on the Placement of ''Ledum''". [[Systematic Botany]].
3. (1985). "The Audubon Society Field Guide to North American Wildflowers, Eastern Region". Knopf.
4. (1997). "A Guide to Wildflowers in Winter: Herbaceous Plants of Northeastern North America". Northeastern Naturalist.
5. (July 2011). "The Biology of Canadian Weeds. 146.Rhododendron groenlandicum(Oeder) Kron and Judd". Canadian Journal of Plant Science.
6. (2003). "Kew, Royal Botanic Gardens of". Oxford University Press.
7. "''Rhododendron groenlandicum''".
8. (1990). "''Rhododendron groenlandicum''". [[Flora of North America]].
9. Anderson, M.. (2011). "Plant Guide for bog Labrador tea (Ledum groenlandicum).". USDA-Natural Resources Conservation Service, National Plant Data Team..
10. (April 2007). "Antioxidant, anti-inflammatory and anticancer activities of methanolic extracts from Ledum groenlandicum Retzius". Journal of Ethnopharmacology.
11. Susan Verberg,The Rise and Fall of Gruit,Copyright © Susan Verberg, 2018.
12. Richard W. Unger, Beer in the Middle Ages and the Renaissance,2004 University of Pennsylvania Press, p31-2