Kalmia
Encyclopedia
Kalmia is a genus
of about 8 species
of evergreen
shrub
s 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 acid
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 to honour his friend the Finnish 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 John 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, simple lanceolate, and arranged spirally on the stems. The flower
s are white, pink or purple, in corymbs of 10-50, reminiscent of Rhododendron
flowers but flatter, with a star-like calyx of five conjoined petal
s; each flower is 1–3 cm diameter. The fruit
is a five-lobed capsule, which splits to release the numerous small seed
s.
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, 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 larva
e of some lepidoptera
n species including Coleophora kalmiella
which feeds exclusively on Kalmia.
The related Kalmiopsis
(Kalmiopsis leachiana) is a rare shrub native to the Siskiyou Mountains
of southwest Oregon
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of about 8 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s from 0.2–5 m tall, in the family Ericaceae
Ericaceae
The Ericaceae, commonly known as the heath or heather family, is a group of mostly calcifuge flowering plants. The family is large, with roughly 4000 species spread across 126 genera, making it the 14th most speciose family of flowering plants...
. They are native to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
(mainly in the eastern half of the continent) and Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
. They grow in acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
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 to honour his friend the Finnish botanist Pehr Kalm
Pehr Kalm
Pehr Kalm was a Swedish-Finnish explorer, botanist, naturalist, and agricultural economist. He was one of most important apostles of Carl Linnaeus...
, who collected it in eastern North America during the mid-18th century. Earlier Mark Catesby
Mark Catesby
Mark Catesby was an English naturalist. Between 1731 and 1743 Catesby published his Natural History of Carolina, Florida and the Bahama Islands, the first published account of the flora and fauna of North America...
saw it during his travels in Carolina
The Carolinas
The Carolinas is a term used in the United States to refer collectively to the states of North and South Carolina. Together, the two states + have a population of 13,942,126. "Carolina" would be the fifth most populous state behind California, Texas, New York, and Florida...
, 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
Viburnum tinus is a species of flowering plant in the genus Viburnum, belonging to the family Adoxaceae. Laurus signifies the leaves' similarities to bay laurel; tinus means "tenth born".-Description: It is a shrub reaching up to 2-7 m tall, with a dense, rounded crown...
"; the botanist and plant-collector John Collinson
John Collinson
John Collinson was an English cricketer who played three first-class matches either side of the Second World War.He appeared twice for Middlesex in August 1939, making his debut against Gloucestershire at Cheltenham...
, 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
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are 2–12 cm long, simple lanceolate, and arranged spirally on the stems. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are white, pink or purple, in corymbs of 10-50, reminiscent of Rhododendron
Rhododendron
Rhododendron is a genus of over 1 000 species of woody plants in the heath family, most with showy flowers...
flowers but flatter, with a star-like calyx of five conjoined petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s; each flower is 1–3 cm diameter. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a five-lobed capsule, which splits to release the numerous small seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s.
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, which may be written with or without the hyphen. (See species list below.) "Kid" here refers to a young goat
Goat
The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...
, not a human child, but the foliage and twigs are toxic to humans as well.
It has also been called spoonwood
Spoonwood
Spoonwood may refer to either of 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....
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
Garden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...
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
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e of some lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
n species including Coleophora kalmiella
Coleophora
Coleophora is a very large genus of moths of the family Coleophoridae. It contains some 1,350 described species. The genus is represented on all continents, but the majority are found in the Nearctic and Palaearctic regions...
which feeds exclusively on Kalmia.
Species
- Kalmia angustifoliaKalmia angustifoliaKalmia angustifolia is a flowering plant in the family Ericaceae, which is often used like an ornamental plant. It has attractive small, deep crimson-pink flowers that occur early summer. The low shrub, a native plant of North America, may be only six inches high, or it may attain three feet...
L. - Sheep-laurel, Lambkill - Kalmia carolina Small - Carolina Mountain-laurel
- Kalmia cuneata Michx. - Whitewicky
- Kalmia ericoides Wright - Cuban Kalmia
- Kalmia hirsuta Walt. - Hairy Mountain-laurel
- Kalmia latifoliaKalmia latifoliaKalmia latifolia, commonly called Mountain-laurel or Spoonwood, is a species of flowering plant in the blueberry family, Ericaceae, that is native to the eastern United States. Its range stretches from southern Maine south to northern Florida, and west to Indiana and Louisiana. Mountain-laurel is...
L. - Mountain-laurelKalmia latifoliaKalmia latifolia, commonly called Mountain-laurel or Spoonwood, is a species of flowering plant in the blueberry family, Ericaceae, that is native to the eastern United States. Its range stretches from southern Maine south to northern Florida, and west to Indiana and Louisiana. Mountain-laurel is...
, Lambkill - Kalmia microphyllaKalmia microphyllaKalmia microphylla, known as alpine laurel, bog laurel, swamp-laurel, western bog-laurel or western laurel, is a species of Kalmia belonging to the Ericaceae family...
(Hook.) A. Heller - Alpine laurel, Alpine Bog-laurel, Alpine Mountain-laurel, sometimes considered a variety or subspecies of Kalmia polifolia - Kalmia occidentalis Small - Synonymous with Kalmia microphyllaKalmia microphyllaKalmia microphylla, known as alpine laurel, bog laurel, swamp-laurel, western bog-laurel or western laurel, is a species of Kalmia belonging to the Ericaceae family...
- Kalmia polifolia Wangenh. - Bog Kalmia, Bog-laurel
The related Kalmiopsis
Kalmiopsis
Kalmiopsis is a small genus of flowering plants in the heath family. It contains two species endemic to Oregon in the United States. This was a monotypic genus containing only Kalmiopsis leachiana until 2007, when a form of it was elevated to species status, Kalmiopsis fragrans....
(Kalmiopsis leachiana) is a rare shrub native to the Siskiyou Mountains
Siskiyou Mountains
The Siskiyou Mountains are a coastal mountain range in the northern Klamath Mountains in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately from east of Crescent City, California northeast along the north side of the Klamath River into...
of southwest Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
.