Kalmia, a genus of handsome flowering, evergreen, North American shrubs of the order ericaceae, named in honor of Peter Kalm. They are popularly known as laurels, but are not related to laurus, the true laurel. The best known and most conspicuous species is the mountain laurel (K. latifolia), a fine shrub, sometimes forming a small tree 15 or 20 ft. high; it is found upon rocky hills, in mountain ravines, as well as in damp rocky pastures, from Canada to Florida. The leaves are scattered, or in whorls or tufts, 2 to 4 in. long, ovate-lanceolate, petioled, somewhat reflexed on the margins, of a bright green color and a leathery texture. The flowers, which vary from pure white to deep rose color, are borne in large terminal heads, and are externally so viscid as to adhere to each other when carelessly plucked. The corolla is beautiful both before and after it opens; in its unexpanded state it has been compared to a"ten-angled casket;" it is monopetalous and salver-shaped or shallow bell-shaped. There are ten stamens, the long filaments of which are arched by each anther being caught in and held by a depression in the corolla; a slight disturbance, such as the entrance of an insect, dislodges the anthers from their niches, and the bowed stamens spring violently upward, the jerk scattering the pollen, which is in this genus liberated from a hole or pore in the apex of each anther cell.
This is one among the many contrivances for securing cross fertilization. The stems and roots afford a favorite material for rustic work; the wood is close-grained and hard, and is used for turning handles for tools and other small wares; from its use in carving, it is in some places called spoonwood, and it is also sometimes called calico bush. The mountain laurel is in Europe one of the most highly prized of American plants, but is rarely seen in our gardens. It is commonly supposed to be impossible to transplant it; but if the head of the tree be severely cut back so that nothing but naked branches are left, and the plant removed to good garden soil in early spring, it will soon throw out new shoots and by autumn be well clothed with foliage. The flowers may be had late in winter by placing bud-bearing branches in water in a warm room. The other species have the same structure in the flowers as the one already described. The low laurel, sheep laurel, or lamb-kill (K. angustifolia) is equally widely distributed, but is much smaller, not growing above 3 ft., and often forming tufts in low grounds.
Its leaves are opposite or in threes, light green above, and pale or whitish below; the small deep crimson flowers are in corymbs, which appear lateral by the growth of the present season's shoots. As indicated by its common names, this shrub has the reputation among farmers of being poisonous to sheep; some have attributed the ill effects upon sheep to the indigestibility of the leaves; but there seems to be no doubt that the foliage of this and the preceding species produces poisonous effects on man, including nausea and temporary blindness, and similar symptoms are observed in sheep, which are relieved by an emetic. The pale laurel (K. glauca) is found in cold peat bogs, usually on mountains from Pennsylvania northward. It is about one foot high, with a straggling stem, opposite, nearly sessile leaves, which are very glaucous beneath, and few-flowered corymbs of lilac-purple flowers. A species peculiar to the southern states from Virginia to Florida is popularly called wicky (K. hirsuta); it differs from the others in having solitary axillary flowers; it does not grow over 18 in. high, and has very small leaves, a decoction of which is used by the negroes to cure diseases of the skin.
The only other species is K. cuneata, a rather uncommon low shrub found in North and South Carolina.