Mountain Laurel


Mountain Laurel

A genus of seven species of evergreen shrubs and small trees occurring in N America and Cuba. All have poisonous foliage. Most species are cultivated for their clusters of exquisite, saucer-shaped, pink to purple or white flowers. Kalmia latifolia is perhaps the most spectacular when in flower, both as a garden plant and in the wild. It is the state flower of both Connecticut and Pennsylvania. The toxicity of K. latifolia is legendary. Game birds and livestock may be poisonous to eat if they have ingested the leaves. According to Pehr Kalm (1715-79), after whom the genus is named, sheep are especially susceptible (hence the common name, lambkill), whereas deer are unharmed (Travels in North America, Vol. 1, 1753). Though the flesh of affected animals is apparently not contaminated, the intestines will cause poisoning if fed to dogs, so that they "become quite stupid, and, as it were, intoxicated, and often fall so sick that they seem to be at the point of death" (Kalm). Symptoms of poisoning in humans include vertigo, headache, loss of sight, salivation, thirst, nausea, vomiting, palpitations, slow pulse, and difficulty in breathing. Kalmia latifolia contains arbutin (as in Arctostaphylos uva-ursi, See bearberry), a urinary antiseptic, but this is of minor importance compared with the plant's narcotic effects.

Shrub or small tree with glossy, leathery, lanceolate leaves, to 5cm (2in) long. Pink to white flowers are borne in corymbs 8-10cm (3-4in) acorss, in late spring and early summer.


Common Name:
Mountain Laurel
Other Names:
Calico bush, ivybush
Botanical Name:
Kalmia latifolia
Genus:
Kalmia
Family:
Ericaceae
Native Location:
Eastern N America
Cultivation:
Acid soil in sun or partial shade. Remove dead flower heads.
Propagation:
By seed sown in spring at 6-12°C (43-54°F) (Species only); by greenwood cuttings in late spring, or semiripe cuttings in summer.
Harvest:
Leaves are picked when plants are flowering and used fresh for infusions, tinctures, and ointments, or dried for powder.
Height:
3m (10ft)
Width:
3m (10ft)
Variations:
Clementine Churchill
Has deep pink buds and flowers.

Elf
Is dwarf, with tiny leaves, 3cm (1¼in) long, pale pink buds, and white flowers.
Height: 1m (3ft)
Width: 1m (3ft)

f. myrtifolia
Is compact, with small leaves and pale pink flowers.
Height: 1.2m (4ft)
Width: 1.2m (4ft).

Ostbo Red
Has red buds and pale pink flowers; the first red-budded kalmia in cultivation, originating in the USA during the 1940s.
Hardiness:
Z4-7
Parts Used:
Leaves
Properties:
An astringent, slightly bitter herb that acts as a cardiac sedative.
Medicinal Uses:
Internally for syphillis, inflammatory fevers, diarrhea, bowel hemorrhage, neuralgia, paralytic conditions, tinnitus, and angina. Externally for herpes, scalp conditions, and skin irritations. For use by qualified practitioners only; seldom used today.
Warning:
All parts, including nectar, are harmful if eaten.
Bibliography:
The Encyclopedia of Herbs by Deni Bown Copyright © 1995, 2005. Dorling Kindersley Limited. pg 249.