Article · Wikipedia archive · Last revised Jun 15, 2026

Rhododendron subsect. Ledum

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.

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Jun 15, 2026
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Rhododendron subsect. Ledum
Rhododendron columbianum (Ledum glandulosum)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Embryophytes
Clade: Tracheophytes
Clade: Spermatophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Ericales
Family: Ericaceae
Genus: Rhododendron
Subgenus: Rhododendron subg. Rhododendron
Section: Rhododendron sect. Rhododendron
Subsection: R. subsect. Ledum
(L.) Kron & Judd
Species

See text

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.

Description

Ledum species often grow together with poisonous plants such as bog-laurel and bog-rosemary, but certain species (e.g. L. groenlandicum and L. palustre) are easily distinguished by the distinctive rust coloured fuzz on the bottom of leaves.

Taxonomy

Reclassification into Rhododendron

Recent genetic evidence has shown that the species previously treated in this genus are correctly placed in the genus Rhododendron, where they are now treated as Rhododendron subsect. Ledum.1 Because some of the species names used in Ledum could not be used in Rhododendron (the names already having been used for other species already in this large genus), new names had to be coined for them.2

Species

The species listed in genus Ledum (accepted and synonyms), with their current accepted names are:

Ledum species Author GBIF status TPL status GBIF Accepted species Author GBIF status TPL Accepted species Author TPL status
Ledum L. AcceptedLedum 1
Ledum angustifolium Hort. ex Lavallée AcceptedLedum 2
Ledum buxifolium Bergius SynonymLedum 3 Kalmia buxifolia (Bergius) Gift & Kron AcceptedKalmia 1
Ledum californicum Kellogg SynonymLedum 4 Ledum glandulosum AcceptedLedum 5
Ledum columbianum Piper SynonymLedum 6 AcceptedLedum 7 Rhododendron columbianum (Piper) Harmaja AcceptedRhody 1
Ledum decumbens (Ait.) Lodd. SynonymLedum 8 Rhododendron tomentosum subsp. decumbens (Aiton) Elven & D.F.Murray AcceptedRhody 2
Ledum decumbens (Ait.) Lodd. ex Steud. SynonymLedum 9 SynonymLedum 10 Rhododendron tomentosum subsp. decumbens (Aiton) Elven & D.F.Murray AcceptedRhody 2 Ledum palustre subsp. decumbens AcceptedLedum 11
Ledum decumbens Small AcceptedLedum 12 AcceptedLedum 13
Ledum glandulosum Nutt. SynonymLedum 14 AcceptedLedum 5 Rhododendron neoglandulosum Harmaja AcceptedRhody 3
Ledum glandulosum subsp. glandulosum SynonymLedum 15 Ledum glandulosum AcceptedLedum 5
Ledum glandulosum var. californicum (Kellogg) C.L.Hitchc. SynonymLedum 16 Ledum glandulosum AcceptedLedum 5
Ledum glandulosum var. glandulosum SynonymLedum 17 Ledum glandulosum AcceptedLedum 5
Ledum groenlandicum Oeder SynonymLedum 18 SynonymLedum 19 Rhododendron groenlandicum (Oeder) K.A.Kron & W.S.Judd AcceptedRhody 4 Ledum palustre subsp. groenlandicum AcceptedLedum 20
Ledum groenlandicum Retz. AcceptedLedum 21
Ledum groenlandicum f. denudatum Vict. & J.Rousseau AcceptedLedum 22
Ledum groenlandicum subsp. glandulosum (Nutt.) Á.Löve & D.Löve SynonymLedum 23 SynonymLedum 24 Rhododendron neoglandulosum Harmaja AcceptedRhody 3 Ledum glandulosum AcceptedLedum 5
Ledum groenlandicum var. aridiphilum D.Löve AcceptedLedum 25
Ledum hypoleucum Kom. SynonymLedum 26 SynonymLedum 27 Rhododendron diversipilosum (Nakai) H.Harmaja AcceptedRhody 5 Rhododendron hypoleucum (Kom.) Harmaja AcceptedRhody 6
Ledum idahoensis AcceptedLedum 28
Ledum macrophyllum Tolm. SynonymLedum 29 AcceptedLedum 30 Rhododendron diversipilosum (Nakai) H.Harmaja AcceptedRhody 5
Ledum maximum (Nakai) A.P.Khokhr. & M.T.Mazurenko SynonymLedum 31 AcceptedLedum 32 Rhododendron tomentosum Harmaja AcceptedRhody 7
Ledum palustre L. SynonymLedum 33 AcceptedLedum 34 Rhododendron tomentosum Harmaja AcceptedRhody 7
Ledum palustre Michx. SynonymLedum 35 Rhododendron groenlandicum (Oeder) K.A.Kron & W.S.Judd AcceptedRhody 4
Ledum palustre f. decumbens (Aiton) Y.L.Chou & S.L.Tung SynonymLedum 36 Ledum palustre subsp. decumbens AcceptedLedum 11
Ledum palustre subsp. angustissimum Worosch. SynonymLedum 37 Rhododendron subulatum (Nakai) Harmaja AcceptedRhody 8
Ledum palustre subsp. decumbens (Aiton) Hultén AcceptedLedum 11
Ledum palustre subsp. diversipilosum Hara SynonymLedum 38 Ledum macrophyllum AcceptedLedum 30
Ledum palustre subsp. groenlandicum (Oeder) Hultén SynonymLedum 39 AcceptedLedum 20 Rhododendron groenlandicum (Oeder) K.A.Kron & W.S.Judd AcceptedRhody 4
Ledum palustre var. angustifolium Hook. AcceptedLedum 40a
Ledum palustre var. angustum E.A.Busch SynonymLedum 41 Ledum palustre AcceptedLedum 34
Ledum palustre var. decumbens Aiton SynonymLedum 42 Ledum palustre subsp. decumbens AcceptedLedum 11
Ledum palustre var. diversipilosum Nakai SynonymLedum 43 SynonymLedum 44 Rhododendron diversipilosum (Nakai) H.Harmaja AcceptedRhody 5 Ledum macrophyllum AcceptedLedum 30
Ledum palustre var. latifolium (Jacq.) Hook. SynonymLedum 45 Rhododendron groenlandicum (Oeder) K.A.Kron & W.S.Judd AcceptedRhody 4
Ledum palustre var. latifolium (Jacq.) Michx. SynonymLedum 46 Rhododendron groenlandicum (Oeder) K.A.Kron & W.S.Judd AcceptedRhody 4
Ledum palustre var. maximum Nakai SynonymLedum 47 Ledum maximum AcceptedLedum 32
Ledum palustre var. palustre SynonymLedum 48 Ledum palustre AcceptedLedum 34
Ledum palustre var. subulatum Nakai SynonymLedum 49 Rhododendron subulatum (Nakai) Harmaja AcceptedRhody 9
Ledum serpyllifolium AcceptedLedum 50
Ledum subulatum (Nakai) A.P.Khokhr. & M.T.Mazurenko SynonymLedum 51 SynonymLedum 52 Rhododendron subulatum (Nakai) Harmaja AcceptedRhody 8 Rhododendron subulatum (Nakai) Harmaja AcceptedRhody 9

Species references

Ledum

  1. GBIF Secretariat, ed. (2016). "Ledum L." GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  2. GBIF Secretariat, ed. (2016). "Ledum angustifolium Hort. ex Lavallée". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  3. TPL Reference: group=Ledum name=tro-50176889 Coming soon
  4. TPL Reference: group=Ledum name=tro-50092423 Coming soon
  5. TPL Reference: group=Ledum name=tro-12300614 Coming soon
  6. GBIF Secretariat, ed. (2016). "Ledum columbianum Piper". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  7. TPL Reference: group=Ledum name=tro-12300613 Coming soon
  8. GBIF Secretariat, ed. (2016). "Ledum decumbens (Ait.) Loddiges". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  9. GBIF Secretariat, ed. (2016). "Ledum decumbens (Ait.) Loddiges ex Steudel". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  10. TPL Reference: group=Ledum name=kew-2349911 Coming soon
  11. TPL Reference: group=Ledum name=kew-2355735 Coming soon
  12. GBIF Secretariat, ed. (2016). "Ledum decumbens Small". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  13. TPL Reference: group=Ledum name=tro-12300073 Coming soon
  14. GBIF Secretariat, ed. (2016). "Ledum glandulosum Nutt". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  15. TPL Reference: group=Ledum name=tro-12302631 Coming soon
  16. TPL Reference: group=Ledum name=tro-12300615 Coming soon
  17. TPL Reference: group=Ledum name=tro-12302504 Coming soon
  18. GBIF Secretariat, ed. (2016). "Ledum groenlandicum Oeder". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  19. TPL Reference: group=Ledum name=kew-2349909 Coming soon
  20. TPL Reference: group=Ledum name=kew-2355734 Coming soon
  21. GBIF Secretariat, ed. (2016). "Ledum groenlandicum Retz". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  22. GBIF Secretariat, ed. (2016). "Ledum groenlandicum f. denudatum Vict. & J.Rousseau". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  23. GBIF Secretariat, ed. (2016). "Ledum groenlandicum var. aridiphilum D.Löve". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  24. TPL Reference: group=Ledum name=tro-50298977 Coming soon
  25. GBIF Secretariat, ed. (2016). "Ledum groenlandicum var. aridiphilum D.Löve". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  26. GBIF Secretariat, ed. (2016). "Ledum hypoleucum Komarov". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  27. TPL Reference: group=Ledum name=tro-12303119 Coming soon
  28. GBIF Secretariat, ed. (2016). "Ledum idahoensis". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  29. GBIF Secretariat, ed. (2016). "Ledum macrophyllum Tolm". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  30. TPL Reference: group=Ledum name=tro-12300074 Coming soon
  31. GBIF Secretariat, ed. (2016). "Ledum maximum (Nakai) A.P.Khokhrjakov & M.T.Mazurenko". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  32. TPL Reference: group=Ledum name=tro-50194624 Coming soon
  33. GBIF Secretariat, ed. (2016). "Ledum palustre L." GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  34. TPL Reference: group=Ledum name=kew-2349893 Coming soon
  35. GBIF Secretariat, ed. (2016). "Ledum palustre Michx". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  36. TPL Reference: group=Ledum name=tro-50156076 Coming soon
  37. GBIF Secretariat, ed. (2016). "Ledum palustre subsp. angustissimum Worosch". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  38. TPL Reference: group=Ledum name=tro-12303120 Coming soon
  39. GBIF Secretariat, ed. (2016). "Ledum palustre subsp. groenlandicum (Oeder) Hulten". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  40. GBIF Secretariat, ed. (2016). "Ledum palustre var. angustifolium Hook". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  41. TPL Reference: group=Ledum name=tro-50156075 Coming soon
  42. TPL Reference: group=Ledum name=kew-2355732 Coming soon
  43. GBIF Secretariat, ed. (2016). "Ledum palustre var. diversipilosum Nakai". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  44. TPL Reference: group=Ledum name=tro-12303121 Coming soon
  45. GBIF Secretariat, ed. (2016). "Ledum palustre var. latifolium (Jacq.) Hook". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  46. GBIF Secretariat, ed. (2016). "Ledum palustre var. latifolium (Jacq.) Michx". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  47. TPL Reference: group=Ledum name=tro-50194625 Coming soon
  48. TPL Reference: group=Ledum name=tro-50156073 Coming soon
  49. TPL Reference: group=Ledum name=tro-50194628 Coming soon
  50. GBIF Secretariat, ed. (2016). "Ledum serpyllifolium". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  51. GBIF Secretariat, ed. (2016). "Ledum subulatum (Nakai) A.P.Khokhrjakov & M.T.Mazurenko". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  52. TPL Reference: group=Ledum name=tro-50194629 Coming soon

Rhododendron

  1. GBIF Secretariat, ed. (2016). "Rhododendron columbianum (Piper) Harmaja". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  2. GBIF Secretariat, ed. (2016). "Rhododendron tomentosum subsp. decumbens (Aiton) Elven & D.F.Murray". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  3. GBIF Secretariat, ed. (2016). "Rhododendron neoglandulosum Harmaja". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  4. GBIF Secretariat, ed. (2016). "Rhododendron groenlandicum (Oeder) K.A. Kron & W.S. Judd". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  5. GBIF Secretariat, ed. (2016). "Rhododendron diversipilosum (Nakai) H. Harmaja". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  6. TPL Reference: group=Rhody name=tro-50303827 Coming soon
  7. GBIF Secretariat, ed. (2016). "Rhododendron tomentosum Harmaja". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  8. GBIF Secretariat, ed. (2016). "Rhododendron subulatum (Nakai) Harmaja". GBIF Backbone Taxonomy. Retrieved 2017-09-20.
  9. TPL Reference: group=Rhody name=tro-50223463 Coming soon

Other

  1. TPL Reference: group=Kalmia name=tro-50310693 Coming soon

Hybrids

Natural hybrids (nothospecies) also occur.

  • Ledum columbianum = Rhododendron × columbianum (R. groenlandicum × R. neoglandulosum) is listed by Harri Harmaja as a natural hybrid.2
  • Rhododendron vanhoeffeni Abromeit3 is a probably hybrid between Ledum palustre subsp. decumbens and Rhododendron lapponicum.2

Uses

Ledum (L. groenlandicum) essential oil in clear glass vial source ↗

Some species (e.g. L. groenlandicum) have been used to produce Labrador tea. Other species have varying levels of toxicity (e.g. L. glandulosum). Evergreen Labrador tea grows slowly, but retains its leaves year-round. Users should take care not to over-harvest leaves from any single plant.

See also

See also

Notes

Notes

  1. This is an inconsistency in GBIF data: the species name is a "Synonym" but a variety is "Accepted".
References

References

  1. Harmaja 1991.
  2. Kihlman 2004
  3. GBIF Secretariat, ed. (2016). "Rhododendron vanhoeffeni Abromeit". GBIF Backbone Taxonomy. Retrieved 2017-09-21.
Bibliography

Bibliography