Labrador tea is a common name for three closely related plant species in the genus Rhododendron as well as a herbal tea made from their leaves. All three species are primarily wetland plants in the heath family. Labrador tea has been a favorite beverage for a long time among Athabaskan First Nations and Inuit.
All three species used to make Labrador tea are low, slow-growing shrubs with evergreen leaves:
The leaves are smooth on top with often wrinkled edges, and fuzzy white to red-brown underneath, and point straight to the sides or downward. [1]
R. tomentosum, R. groenlandicum, and R. neoglandulosum can be found in wetlands and peat bogs. [1]
The Athabaskans and other indigenous peoples brew the leaves as a beverage. [1] The Pomo, Kashaya, Tolowa and Yurok of Northern California boil the leaves of western Labrador tea similarly, to make a medicinal herbal tea to help with coughs and colds. [2] Botanical extracts from the leaves have been used to create natural skin care products by companies in Quebec and Newfoundland and Labrador. Others use Labrador tea to spice meat by boiling the leaves and branches in water and then soaking the meat in the decoction.[ citation needed ]
During the eighteenth century, German brewers used R. tomentosum while brewing beer to make it more intoxicating, but it became forbidden because it led to increased aggression. [1]
There is no sufficient data that demonstrates Labrador tea is safe to consume, as toxicity varies across species and localities. Excessive consumption is not recommended due to diuresis, vomiting, dizziness, and drowsiness. [1] Large doses can lead to cramps, convulsions, paralysis, and, in rare cases, death. [1]
Toxicity occurs due to terpenoid ledol found in all Labrador tea species. R. groenlandicum has the lowest toxicity due to lower levels of ledol. Grayanotoxins are also present, but few lethal human cases of poisoning due to grayanotoxins in Labrador tea have been documented. However, lethal poisonings have been documented in livestock. [1]
Tea leaves are collected from multiple plants in the spring. Labrador tea is slow-growing, so only a single new leaf is collected from a plant every other year, to avoid damaging individual plants. [1]
Herbal teas, technically known as herbal infusions, and less commonly called tisanes, are beverages made from the infusion or decoction of herbs, spices, or other plant material in hot water. Often herb tea, or the plain term tea, is used as a reference to all sorts of herbal teas. Many herbs used in teas/tisanes are also used in herbal medicine and in folk medicine.
Rhododendron is a very large genus of about 1,024 species of woody plants and in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan region, but smaller numbers occur elsewhere in Asia, and in North America, Europe and Australia.
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 is also known as andromedotoxin, acetylandromedol, rhodotoxin and asebotoxin. Grayanotoxins are produced by Rhododendron species and other plants in the family Ericaceae. Honey made from the nectar and so containing pollen of these plants also contains grayanotoxins and is commonly referred to as mad honey.
Kalmia is a genus of about ten species of evergreen shrubs from 0.2–5 m tall, in the family Ericaceae (heath). They are native to North America and Cuba. They grow in acidic soils, with different species in wet acid bog habitats and dry, sandy soils.
Peumus boldus, commonly known as boldo, is a species of tree in the family Monimiaceae and the only species in the genus Peumus. It is endemic to the central region of Chile, between 33° and 40° southern latitude. Boldo has also been introduced to Europe and North Africa, though it is not often seen outside botanical gardens.
Ledum was a genus in the family Ericaceae, including eight species of evergreen shrub native to cool temperate and subarctic regions of the Northern Hemisphere and commonly known as Labrador tea. It is now recognised as a subsection of section Rhododendron, subgenus Rhododendron, of the genus Rhododendron.
Rhododendron groenlandicum is a flowering shrub with white flowers and evergreen leaves that is used to make a herbal tea.
Rhododendron tomentosum, commonly known as marsh Labrador tea, northern Labrador tea, marsh rosemary or wild rosemary, is a flowering plant in the subsection Ledum of the large genus Rhododendron in the family Ericaceae.
Kalmia polifolia, previously known as Kalmia glauca and commonly called bog laurel, swamp laurel, or pale laurel, is a perennial evergreen shrub of cold acidic bogs, in the family Ericaceae. It is native to north-eastern North America, from Newfoundland to Hudson Bay southwards.
Rhododendron luteum, the yellow azalea or honeysuckle azalea, is a species of flowering plant in the heath family Ericaceae, native to southeastern Europe and southwest Asia. In Europe, it occurs from southern Poland and Austria, south through the Balkans, and east to southern Russia; and in Asia, east to the Caucasus.
The Lime Hollow Center for Environment and Culture is a nature preserve project in Cortland County, New York. It was founded in 1993 as the Lime Hollow Nature Center, the culmination of efforts 20 years earlier to develop a nature preserve to protect an unusual assemblage of marl ponds, a peat bog, and kame-and-kettle topography along an abandoned railroad right of way in Lime Hollow, just west of the city of Cortland.
Rhododendron periclymenoides, the pink azalea or pinxter flower, is a species of shrub in the heath family Ericaceae. It is native to eastern North America, where it is widespread from Alabama to New Hampshire. It is often found in riparian areas, in wet to dry forests.
Geocaulon is a monotypic genus of flowering plants in the family Santalaceae containing the single species Geocaulon lividum, which is known by the common names northern comandra and false toadflax. It is native to northern North America, where it is common and widespread from Alaska to Newfoundland and into the northernmost contiguous United States.
Masala chai is a popular beverage throughout South Asia, originating in India. It is made by brewing black tea in milk and water, and then by sweetening with sugar. Adding aromatic herbs and spices creates masala chai, although chai is often prepared unspiced.
Rhododendron columbianum, commonly known as western Labrador tea, swamp tea, or muskeg tea, is a shrub that is widespread in the western United States and in western Canada, reported from British Columbia, Alberta, Washington, Oregon, Idaho, California, Montana, Wyoming, Utah, Nevada, and Colorado. It grows in wet places from sea level up to 3,500 m (11,000 ft). It was formerly known as Ledum columbianum. Its origins date back to the late Pliocene.
Ledol is a poisonous sesquiterpene that can cause cramps, paralysis, and delirium. Caucasian peasants used Rhododendron plants for these effects in shamanistic rituals.
Chrysomyxa nagodhii is a species of rust fungus in the family Coleosporiaceae. It was described as new to science by Canadian mycologist Patricia E. Crane in 2001. It probably occurs throughout the range of Ledum decumbens and Rhododendron groenlandicum. On Picea, spermogonia and aecia occur on distinct rusty yellow bands on current-year needles.
Kathleen Anne Kron is a retired biology professor from Wake Forest University. She is known for her research on Ericaceae, a family of flowering plants.