Calmium

The scientific name of the genus is derived from the surname Pera Kalma (1716-1779), a Swedish ( Finnish ) botanist, professor at the Royal Academy of Abo ( Turku ), and a student of Karl Linnaeus . Kalm was one of the Apostles of Linnaeus , participated in an expedition to North America (1747-1751), and later, returning to his homeland, grew some North American plant species, including narrow-leaved calcium ( Kalmia angustifolia ) ^[3] , which at that time was attributed to the genus Hamedafne ( Chamaedaphne ). In 1753, in his work Species plantarum, Linnaeus identified a new genus Kalmia , naming it in honor of his student ^[4] ; Linnaeus included narrow-leaved calcium and broad-leaved calcium ( Kalmia latifolia ) in this genus.

Occasionally in literature there is another Russian name for the genus - Kalmya ^[5] .

Plants of this genus are common in North America , reaching in the north to Alaska ^[6] . Plants grow in undergrowth, at the edge of forests, through swamps ^[4] .

Kalmyas are evergreen shrubs, depending on the species, from half a meter to several meters tall.

Plants of this genus are distinguished by an original device for cross-pollination : the stamen, in the process of its growth inside the still unopened flower, falls with its upper part into the pocket-shaped limbs found on the petals . When the corolla begins to open, the petals also carry the stamens, resulting in tension in the stamens. After that, if a sufficiently heavy insect sits on the flower, the stamens are displaced and leave the limbs of the petals, after which, under the action of the springy stamen filament, they straighten and, clapping the anther on the insect, showered with pollen ^[7] .

In spring or early summer, flowers bloom on plants in large numbers - depending on the species, they can be small and quite large, the color of their corollas can be white, pink or reddish-pink; all species are characterized by long stamens ^[6] .

All types of calcium contain in their vegetative and generative organs the glycoside andromedotoxin . Its content in calcium is so high that even meat of animals that ate calcium leaves can become poisonous to humans.

Calmium has been known in culture since 1736; the first cultivated species was Kalmy angustifolia (until 1753, the plant was known as Hamedaphne narrow-leaved) ^[4] . It is this species that is the only one suitable for cultivation in Central Russia ^[8] ; in other regions, broad-leaved Kalmya ( Kalmia latifolia ) and multi-leaved Calmium ( Kalmia polifolia ) are also grown .

Calmies are the most frost-resistant broad-leaved evergreens: some species withstand temperatures up to minus 40 ° C ^[6] .

Calmiums do not tolerate stagnation of water, so they should be planted in well- drained or elevated areas. Only acidic soils ( pH 5.5) are suitable for calcium, the presence of lime in the soil, as well as the use of limestone crushed stone as drainage, is unacceptable. The presence of chlorine in the soil is also unacceptable. It is desirable that the soil is loose and fertile. When preparing the soil, leaf soil , horse peat and needles are added to the planting pit ^{[6] [8]} .

Leaves of calcium can be damaged by the bright spring sun, therefore it is better to plant plants in the shade of trees ^[8] .

The current care for calcium is spring mulching of the soil around the bushes and the removal of wilted flowers after flowering. Plants can be fed with the same mineral fertilizers as rhododendrons . Watering calcium usually should not be done, with the exception of a period of intense heat in the absence of rain: in this case, plants are regularly watered with soft water . The calcium bushes do not grow much, individual branches do not dry out, so there is no need for regular pruning of calcium ^[8] .

Propagation of plants - by seeds in the fall; layering , summer green cuttings ^{[6] [8]} .

According to the database of The Plant List (2013), the genus includes 10 species ^[2] :

• Kalmia angustifolia L. - Narrow-leaved calcium , also known as “sheep’s laurel”. View from eastern North America. Under natural conditions, shrubs are found in mountain forests - in the undergrowth and at the edges ^[3] .
• Kalmia buxifolia ( PJBergius ) Gift & Kron - Calcium boxwood . Evergreen shrub up to 1 m high, distributed in the eastern United States.
• Kalmia carolina Small - Caroline Calmia
• Kalmia cuneata Michx. - Wedge-shaped calcium . Deciduous shrub up to 2 m high, endemic to North and South Carolina .
• Kalmia ericoides C. Wright ex Griseb. - Calcium heather ^[9] . It grows in Cuba.
• Kalmia hirsuta Walter - Shaggy Kalmya
• Kalmia latifolia L. typus ^[10] - Broad-leaved calcium , also known as "mountain laurel". This species is larger than others: it grows up to two and a half meters in height, its flowers - with a diameter of up to 2.5 cm. The corolla is pink. Additional decorativeness of flowering plants is associated with the contrasting color of red buds and pink flowers ^[8] .
• Kalmia microphylla ( Hook. ) A.Heller - Small-leaved calcium . Evergreen shrub up to 0.6 m high. Distributed in western North America from California to Alaska.
• Kalmia polifolia Wangenh. - Calcium multifoliate , also known as “swamp laurel”. Relatively low shrub with flowers up to 1.8 cm in diameter. Corolla is purple-pink ^[8] .
• Kalmia simulata ( Britton & M. Wilson ) Southall - Imaginary Calmy

A rather large number of species names of this genus in The Plant List (2013) have the status of unresolved name , that is, it cannot be said with respect to them whether they should be used - or they should be reduced to the synonymy of other species.

Some species, which are sometimes included in the genus Calmium in the literature, in the The Plant List (2013) database belong to other genera: for example, the species Kalmia procumbens ( L. ) Gift , Kron & PFStevens ex Galasso , Banfi & F.Conti ( Kalmiya lying ) is considered as part of the monotypic genus Loiseleuria ( Loiseleuria ) and its correct name is Loiseleuria procumbens ( L. ) Loisel. ^[11] .

• Vermeilen N. Kalmia latifolia - Broad-leaved Kalmy // Useful herbs. Illustrated Encyclopedia / Per. with eng. B. N. Golovkina. - M .: Labyrinth Press, 2002 .-- S. 162. - 320 p. - ISBN 5-9287-0244-2 .
• Kalmia // Botany. Encyclopedia "All plants of the world": Per. from English = Botanica / ed. D. Grigoriev et al. - M .: Könemann, 2006 .-- S. 496. - 1020 p. - ISBN 3-8331-1621-8 .
• Kozhevnikov Yu. P. Plant life : in 6 volumes / ch. ed. A. L. Takhtadzhyan . - M .: Education , 1981. - T. 5. Part 2: Flowering plants / ed. A. L. Takhtadzhyana. - 512 s. - 300,000 copies.
• Kalmy // Animals and plants. Illustrated Encyclopedic Dictionary / Scientific. ed. Editions T. M. Chukhno. - M .: Eksmo, 2007 .-- S. 507. - 1248 p. - ISBN 5-699-17445-1 .

• Prikhodko M. A. Kalmiya - a great addition to heather.
• European Kalmia Society (English) (Retrieved January 7, 2010)