Kalmia

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Ordo: Ericales

Familia: Ericaceae
Subfamilia: Ericoideae
Tribus: Phyllodoceae
Genus: Kalmia
Species: K. angustifolia – K. buxifolia – K. ciliata – K. cuneata – K. ericoides – K. ferruginosa – K. hirsuta – K. intermedia – K. lanceolata – K. latifolia – K. microphylla – K. polifolia – K. procumbens

Source(s) of checklist:

Govaerts, R. et al. 2020. Kalmia in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2020 May 06. Reference page.

Name

Kalmia L., Sp. Pl. 1: 391. 1753; Gen Pl., ed. 5: 185. 1754.

Lectotype species: Kalmia latifolia L. (designated by N.L. Britton & A. Brown, Ill. Fl. N.U.S. ed. 2. 2: 683. 7 Jun 1913, supported by Hitchcock, Prop. Brit. Bot. 153. Aug 1929)

Synonyms

Heterotypic
Ammyrsine Pursh, Fl. Amer. Sept. 1: 280, 301. 1814.
Type species: A. buxifolia (Bergius) Pursh
Azalea L., Sp. Pl. 150. 1753, nom. rej.
Type species: A. procumbens L.
Chamaecistus Oeder, Fl. Danica 4. t. 9. 1762.
Type species: C. procumbens (L.) Kuntze
Chamaeledon Link, Enum. Pl. Horti Berol. 1: 210. 1821.
Type species: C. procumbens (L.) Link
Dendrium Desv., J. Bot. Agric. 1: 36. 1813.
Type species: D. buxifolia (Bergius) Desv.
Fischera Sw., Mém. Soc. Imp. Naturalistes Moscou 5: 14. 1817.
Kalmiella Small, Fl. Southeast. U. S. 886. 1903.
Type species: K. hirsuta (Walter) Small
Leiophyllum (Pers.) Elliott, Sketch Bot. S.-Carolina Georgia 1: 483. 1817, nom. illeg. non R.A.Hedwig (1806).
Type species: L. buxifolium (Bergius) Elliott
Loiseleuria Desv., J. Bot. Agric. 1: 35. 1813, nom. cons.
Type species: L. procumbens (L.) Desv.
Tsutsusi Adans., Fam. Pl. 2: 164. 1763.

Notes
Homonyms

Chamaedaphne Catesby ex Kuntze, Rev. Gen. 2: 388. 5 Nov 1891, nom. illeg. non J.Mitchell (1769), nom. rej., nec Moench (1794), nom. cons.

References
Primary references

Linnaeus, C. 1753. Species Plantarum. Tomus I: 391. Reference page.
Linnaeus, C. 1754. Genera Plantarum, ed. 5: 185. Reference page.

Additional references

Britton, N.L. & Brown, A. 1913. An illustrated flora of the northern United States, Canada and the British possessions: from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian. ed. 2. C. Scribner's sons, New York. Vol. 2: 683. Reference page.
Hitchcock, A.S. & Green, M.L. 1929. Standard species of Linnaean genera of Phanerogamae (1753–1754). pp. 111–195 in International Botanical Congress. Cambridge (England), 1930. Nomenclature. Proposals by British Botanists. His Majesty's Stationery Office, London. Biblioteca Digital Reference page.
Kron, K.A., Judd, W.S. & Anderberg, A.A. 2008. Validation of Kalmia buxifolia (Bergius) Gift & Kron and Kalmia procumbens (L.) Gift & Kron. Nordic Journal of Botany 26(1): 47–48. DOI: 10.1111/j.0107-055X.2008.00168.x Reference page.

Links

Govaerts, R. et al. 2020. Kalmia in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2020 Jan. 19. Reference page.
Hassler, M. 2020. Kalmia. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2020. Species 2000 & ITIS Catalogue of Life. Published on the internet. Accessed: 2020 Jan. 19. Reference page.
International Plant Names Index. 2016. Kalmia. Published online. Accessed: May 9 2016.
Tropicos.org 2016. Kalmia. Missouri Botanical Garden. Published on the internet. Accessed: 2016 May 9.

Vernacular names
Deutsch: Lorbeerrosen
English: Lambkill, Spoonwood
suomi: Kalmiat
Nederlands: Laurierroos, Lepelstruik
polski: Kalmia
svenska: Kalmiasläktet

Kalmia is a genus of about ten species of evergreen shrubs from 0.2–5 m tall, in the family Ericaceae. They are native to North America (mainly in the eastern half of the continent) and Cuba. They grow in acidic soils, with different species in wet acid bog habitats (K. angustifolia, K. polifolia) and dry, sandy soils (K. ericoides, K. latifolia).

Kalmia was named by Linnaeus to honour his friend the botanist Pehr Kalm, who collected it in eastern North America during the mid-18th century. Earlier Mark Catesby saw it during his travels in Carolina, and after his return to England in 1726, imported seeds. He described it, a costly rarity, in his Natural History of Carolina, as Chamaedaphne foliis tini, that is to say "with leaves like the Laurustinus"; the botanist and plant-collector Peter Collinson, who had begged some of the shrub from his correspondent John Custis in Virginia, wrote, when his plants flowered, that "I Really Think it exceeds the Laurus Tinus."[1]
Mountain laurel blooms showing the conjoined petals

The leaves are 2–12 cm long and simple lanceolate. The flowers are white, pink or purple, in corymbs of 10-50, reminiscent of Rhododendron flowers but flatter, with a star-like calyx of five conjoined petals; each flower is 1–3 cm diameter. The fruit is a five-lobed capsule, which splits to release the numerous small seeds.

The foliage is toxic if eaten, with sheep being particularly prone to poisoning, hence the name lambkill used for some of the species. Other names for Kalmia, particularly Kalmia angustifolia, are sheep-laurel, lamb-kill, calf-kill, kill-kid, and sheep-poison,[2] which may be written with or without the hyphen. (See species list below.) "Kid" here refers to a young goat, not a human child, but the foliage and twigs are toxic to humans as well.

It has also been called spoonwood because Kalm was told by Dutch settlers of North America that Native Americans made spoons from the wood.[3] Given its toxicity, this may be folklore rather than scientific fact.

Kalmias are popular garden shrubs, grown for their decorative flowers. They should not be planted where they are accessible to livestock due to the toxicity.

Kalmia species are used as food plants by the larvae of some lepidopteran species including Coleophora kalmiella which feeds exclusively on Kalmia.

Species
Kalmia microphylla

Species (and infraspecific taxa) listed by The Plant List as "Accepted":[4]

Kalmia angustifolia L. - Sheep-laurel, lambkill
Kalmia buxifolia (Bergius) Gift & Kron - Sandmyrtle
Kalmia carolina Small - Carolina mountain-laurel
Kalmia cuneata Michx. - Whitewicky
Kalmia ericoides C.Wright ex Griseb. - Cuban kalmia
Kalmia ericoides var. aggregata (Small) Ebinger
Kalmia hirsuta Walter - Hairy mountain-laurel
Kalmia latifolia L. - Lambkill
Kalmia latifolia f. alba (Mouill.) Rehder
Kalmia latifolia f. fuscata (Rehder) Rehder
Kalmia latifolia f. obtusata (Rehder) Rehder
Kalmia latifolia f. polypetala (G.Nicholson) Rehder
Kalmia microphylla (Hook.) A.Heller - Alpine laurel, alpine bog-laurel, alpine mountain-laurel
Kalmia microphylla subsp. occidentalis (Small) Roy L.Taylor & MacBryde
Kalmia polifolia Wangenh. - Bog kalmia, bog-laurel
Kalmia simulata (Britton & M.Wilson) Southall

Kalmia procumbens is a widely accepted member of this genus,[5][6] though it is the only species in the genus Loiseleuria according to The Plant List.[4] The related Kalmiopsis (Kalmiopsis leachiana and K. fragrans) is a rare shrub endemic to southwest Oregon.

Kalmia angustifolia

Kalmia buxifolia

Kalmia latifolia

Kalmia microphylla

Kalmia polifolia

Fossil record

Fossil leaves of †Kalmia saxonica have been described from the Lower Miocene of Brandis, Germany and Bełchatów, Poland, †'Kalmia marcodurensis have been described from the Lower Miocene of Bitterfeld, Germany. In the Late Tertiary Kalmia was associated with coal-forming vegetation occurring as a component of the vegetation of bush swamps together with Cyrilla and other shrubs. Among recent species Kalmia angustifolia is most similar to †Kalmia saxonica in respect of morphology, while Kalmia latifolia has a very similar epidermal structure. These two extant species grow in the eastern part of North America from (Quebec to Florida) on acid swampy or marshy soils.[7]

Bibliography
Books

Jaynes, Richard A., 1997: Kalmia, mountain laurel and related species, Timber Press, Portland, Oregon, U.S.A.

Huebbers, Karl-Heinz and Westhoff, Julia,2020 : Fascynujące kalmie (Fascinating Kalmie) published by Plantin, Krakow, Poland

ISBN: 978-83-956964-0-4
References

Alice M. Coats, Garden Shrubs and Their Histories (1964) 1992, s.v. "Kalmia".
Natural History Education, Science, Technology regarding alternate names, accessed March 30, 2007.
Plants of Colonial Days by Raymond Leech Taylor, p. 61. (1996) ISBN 0-486-29404-8. Accessed March 30, 2007.
"The Plant List". Version 1.1. 2013. Retrieved 2017-10-22 – via Internet.
"Kalmia procumbens in Flora of North America @ efloras.org". www.efloras.org. Retrieved 2019-03-13.
"Kalmia procumbens (Alpine-azalea): Go Botany". gobotany.nativeplanttrust.org. Retrieved 2019-03-13.
Acta Palaeobotanica - Supplementum No. 3 - New Fossil Floras from Neogene Deposits in the Bełchatów Lignite Mine by Grzegor Worobiec - Polish Academy of Sciences, W. Szafer Institute of Botany, Krakow 2003