- Rhododendron tomentosum (Northern Labrador tea, previously Ledum palustre),
- Rhododendron groenlandicum, (Bog Labrador tea, previously Ledum groenlandicum or Ledum latifolium) and
- Rhododendron neoglandulosum, (Western Labrador tea, or trapper's tea, previously Ledum glandulosum).
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. The tiny white flowers grow in hemispherical clusters and are very fragrant and sticky and highly attractive to bees.
The Athabaskans brew the leaves as a beverage and some people chew the raw leaves because they enjoy the flavor. Others use Labrador tea to spice meat by boiling the leaves and branches in water and then soaking the meat in the decoction.
The Pomo, Kashaya, Tolowa and Yurok of Northern California boiled the leaves of Western Labrador Tea similarly, to make a medicinal herbal tea. In Greenland, this is still the case. Here it is also used in facial steam bath.
Labrador tea has narcotic properties. Evidence suggests that excessive consumption of the plant may cause delirium or poisoning. Toxic terpenes of the essential oils cause symptoms of intoxication, such as slow pulse, lowering of blood pressure, lack of coordination, convulsions, paralysis, and death. It is apparently safe as a weak herbal tea, but should not be made too strong.
Rhododendron groenlandicum grows in bogs and wet shores, and sometimes on rocky alpine slopes. Both species are generally northern (north temperate to tundra) in distribution, with the range of R. groenlandicum somewhat farther south.
Rhododendron tomentosum, Rhododendron groenlandicum, and Rhododendron neoglandulosum grow slowly, so pick individual leaves rather than whole branches, and harvest from different shrubs. In addition, Labrador tea grows in abundance in large patches so it should not be difficult to move from plant to plant to avoid over-harvesting. Labrador tea is an evergreen plant and will be available all year long.