''Kalmia angustifolia'' is a flowering

shrub A shrub (often also called a 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 ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Ericaceae The Ericaceae are a 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 c.4250 known species spread across 124 genera, making it th ...

, 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 Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, ...

, and may become dominant over large areas after fire or logging. Like many plant species of infertile habitats it has

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

leaves and

mycorrhiza A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant ...

l associations with fungi. It is also found in drier area of peat

bogs A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main Wetland#Types, types of wetlands. Other names for bogs include mire, mosses, quagmire, ...

Description

The attractive small, deep crimson-pink flowers are produced in early summer. Each has five sepals, with a corolla of five fused petals, and ten stamens fused to the corolla. They are pollinated by bumble bees and solitary bees. Each mature capsule contains about 180 seeds.Hall, I. V., Jackson, L. P. and Everett, C. F. 1973. The biology of Canadian weeds. 1. ''Kalmia angustifolia'' L. Canadian Journal of Plant Science 53: 865–873. In the wild the plant may vary in height from . New shoots arise from dormant buds on buried rhizomes. This process is stimulated by fire. The narrow

leaves, pale on the underside, have a tendency to emerge from the stem in groups of three. The Latin

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''angustifolia'' means "narrow-leaved". A peculiarity of the plant is that clusters of leaves usually terminate the woody stem, for the flowers grow in whorls or in clusters below the stem apex.

Cultivation

''Kalmia angustifolia'' is cultivated as an ornamental garden shrub. It prefers a moist,

acidic In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

soil in partial shade. The species has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

. Numerous

cultivars A cultivar is a type of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and when Plant propagation, propagated retain those traits. Methods used to propagate cultivars include: division, root and st ...

have been selected for garden use, of which ''K. angustifolia'' f. ''rubra'', with rich red flowers, has also won the award.

Toxicity

''Kalmia'' contains a

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

, known as

andromedotoxin Grayanotoxins are a group of closely related neurotoxins named after '' Leucothoe grayana'', a plant native to Japan originally named for 19th century American botanist Asa Gray. Grayanotoxin I (grayanotaxane-3,5,6,10,14,16-hexol 14-acetate) is als ...

. It is poisonous to mammals. Hence, it can be unwelcome in pastures. Several of its folk-names testify to the plant's toxicity: 'lamb-kill', 'sheep kill', 'calf-kill', 'pig laurel', 'sheep-laurel' and 'sheep-poison'. It is also known as narrow-leaved laurel and dwarf laurel.

References

{{Taxonbar, from=Q3192236 angustifolia Flora of the Northeastern United States Flora of the Southeastern United States Flora of the Great Lakes region (North America) Flora of Eastern Canada Flora of Saint Pierre and Miquelon Flora of the Appalachian Mountains Plants described in 1753 Taxa named by Carl Linnaeus Flora without expected TNC conservation status