''Kalmia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of about ten

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s from 0.2–5 m tall, in the family

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

(heath). They are native to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

(mainly in the eastern half of the continent) and

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

. They grow in

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

ic 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 Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

to honour his friend the botanist

Pehr Kalm Pehr Kalm (6 March 1716 – 16 November 1779), also known as Peter Kalm, was a Swedish-Finnish List of explorers, explorer, botany, botanist, natural history, naturalist, and Agricultural economics, agricultural economist. He was one of the most ...

, who collected it in eastern North America during the mid-18th century. Earlier,

Mark Catesby Mark Catesby (24 March 1683 – 23 December 1749) was an English natural history, naturalist who studied the flora and fauna of the New World. Between 1729 and 1747, Catesby published his ''Natural History of Carolina, Florida and the Bahama ...

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 ''Viburnum tinus'', the laurustinus, laurustine or laurestine, is a species of flowering plant in the family (biology), family Adoxaceae, native plant, native to the Mediterranean area of Europe and North Africa. ''Laurus'' signifies the leaves' ...

"; 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." The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are 2–12 cm long and simple lanceolate. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are white, pink or purple, in corymbs of 10–50, reminiscent of

Rhododendron ''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...

flowers but flatter, with a star-like calyx of five conjoined

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s; each flower is 1–3 cm diameter. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a five-lobed capsule, which splits to release the numerous small

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s. The foliage contains

grayanotoxin 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 (grayanotoxane-3,5,6,10,14,16-hexol 14-acetate) is also known ...

s, a group of closely related

neurotoxin Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...

s named after ''

Leucothoe grayana ''Eubotryoides grayana'' (syn. ''Leucothoe grayana''), is a species of flowering plant in the family Ericaceae, native to the southern Kuril Islands and to northern and central Japan. It is the sole member of its genus, ''Eubotryoides''. A highly ...

'', native to Japan, so it is toxic if eaten, with

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

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,Natural History Education, Science, Technology
regarding alternate names, accessed March 30, 2007. which may be written with or without the hyphen. (See species list below.) "Kid" here refers to a young

goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...

, not a human child, but the foliage and twigs are toxic to humans as well. It has also been called

spoonwood Spoonwood is a common name for two plants: *''Kalmia latifolia'', a North American plant known as mountain laurel and numerous other names emphasizing its poisonous nature, such as lambkill, kill-kid, and calf-kill. *''Trichilia ''Trichilia'' is ...

because Kalm was told by Dutch settlers of North America that Native Americans made spoons from the wood. Given its toxicity, this may be folklore rather than scientific fact. Kalmias are popular

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

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

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of some

lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

n species including ''

Coleophora kalmiella ''Coleophora kalmiella'' is a moth of the family Coleophoridae. It is found in Canada, including Nova Scotia. The larvae feed on the leaves of ''Kalmia ''Kalmia'' is a genus of about ten species of evergreen shrubs from 0.2–5 m tall, in th ...

'' which feeds exclusively on ''Kalmia''.

Species

Species and subspecies listed by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

: * ''

Kalmia angustifolia ''Kalmia angustifolia'' is a flowering shrub in the family Ericaceae, commonly known as sheep laurel. It is distributed in eastern North America from Ontario and Quebec south to Virginia. It grows commonly in dry habitats in the boreal forest, a ...

'' L. - Sheep-laurel, lambkill ** ''Kalmia angustifolia'' subsp. ''carolina'' (Small) A.Haines - Carolina mountain-laurel * '' Kalmia buxifolia'' (P.J. Bergius) Gift & Kron - Sandmyrtle * '' Kalmia cuneata'' Michx. - Whitewicky * '' Kalmia ericoides'' C.Wright ex Griseb. - Cuban kalmia * '' Kalmia hirsuta'' Walter - Hairy mountain-laurel * ''

Kalmia latifolia ''Kalmia latifolia'', the mountain laurel, calico-bush, or spoonwood, is a flowering plant and one of the 10 species in the genus of Kalmia belonging to the heath(er) family Ericaceae. It is native to the eastern United States. Its range stretch ...

'' L. - Mountain laurel * ''

Kalmia microphylla ''Kalmia microphylla'', known as alpine laurel, bog laurel, swamp-laurel, western bog-laurel or western laurel, is a species of ''Kalmia'' of the family Ericaceae. It is native to North America and can be found throughout the western US and weste ...

'' (Hook.) A.Heller - Alpine laurel, alpine bog-laurel, alpine mountain-laurel ** ''Kalmia microphylla'' subsp. ''occidentalis'' (Small) Roy L.Taylor & MacBryde * ''

Kalmia polifolia ''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, f ...

'' Wangenh. - Bog kalmia, bog-laurel * ''

Kalmia procumbens ''Kalmia procumbens'', commonly known as alpine azalea or trailing azalea, is a dwarf shrub of high mountain regions of the Northern Hemisphere that usually grows no more than tall. Originally named by Linnaeus as ''Azalea procumbens'', it is al ...

'' (L.) Gift, Kron & P.F.Stevens ex Galasso, Banfi & F.Conti ''

'' was treated as the only species in the genus ''Loiseleuria'' in older floras. The related ''

Kalmiopsis leachiana ''Kalmiopsis leachiana'', commonly referred to as Siskiyou kalmiopsis, is a rare flowering plant endemic to the Siskiyou Mountains of southwest Oregon, where it is specially protected in the Kalmiopsis Wilderness reserve. It was discovered in 1 ...

'' and '' K. fragrans'' are rare shrubs

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to southwest

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

. File:FFH-Gebiet "Altwarmbüchener Moor" (cropped).JPG, ''Kalmia angustifolia'' File:Kalmia buxifolia NRCS-2.jpg, ''Kalmia buxifolia'' File:Mountain Laurel - Flickr - treegrow (13).jpg, ''Kalmia latifolia'' File:Western Bog Laurel (cropped).jpg, ''Kalmia microphylla'' File:Kalmia polifolia.jpg, ''Kalmia polifolia''

Fossil record

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

leaves of †''Kalmia saxonica'' have been described from the

Lower Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

Brandis Brandis () is a town in the Leipzig district, in Saxony, Germany. It is situated 16 km east of Leipzig. Geography Brandis developed as a village around Brandis manor house A manor house was historically the main residence of the lord ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

and

Bełchatów Bełchatów () is a city in central Poland with a population of 55,583, as of December 2021. It is located in Łódź Voivodeship, southwest of Warsaw. The Bełchatów Power Station, Elektrownia Bełchatów, located in Bełchatów, is the largest ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

, †Kalmia marcodurensis'' have been described from the Lower Miocene of

Bitterfeld Bitterfeld () is a town in the district of Anhalt-Bitterfeld, Saxony-Anhalt, Germany. Since 1 July 2007 it has been part of the town of Bitterfeld-Wolfen. It is situated approximately 25 km south of Dessau, and 30 km northeast of Hall ...

. In the Late Tertiary ''Kalmia'' was associated with coal-forming vegetation occurring as a component of the vegetation of bush swamps together with ''

Cyrilla ''Cyrilla racemiflora'', the sole species in the genus ''Cyrilla'', is a flowering plant in the family Cyrillaceae, native to warm temperate to tropical regions of the Americas, from the southeastern United States (coastal areas from southeastern ...

'' and other shrubs. Among recent species ''

'' is most similar to †''Kalmia saxonica'' in respect of morphology, while ''

'' has a very similar epidermal structure. These two extant species grow in the eastern part of

from (

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

) on acid swampy or marshy soils.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

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

References

External links

European Kalmia SocietyKalmia.info: German Kalmia hybridizersPieris.eu: Info about ''Kalmia latifolia''
{{Authority control Ericaceae genera Taxa named by Carl Linnaeus