Kalmia Latifolia Clementine Churchill

''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."

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 contains grayanotoxins, a group of closely related neurotoxins named after ''Leucothoe grayana'', native to Japan, so it 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,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, 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. 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

Species (and infraspecific taxa) listed by The Plant List as "Accepted":
* ''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, though it is the only species in the genus ''Loiseleuria'' according to The Plant List. The related '' Kalmiopsis'' ('' Kalmiopsis leachiana'' and '' K. fragrans'') is a rare shrub endemic to southwest Oregon.

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

References

External links

European Kalmia SocietyKalmia.info: German Kalmia hybridizersPieris.eu: Info about ''Kalmia latifolia''

{{Taxonbar, from=Q1427635

Ericaceae genera
Taxa named by Carl Linnaeus