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MOUNTAIN LAUREL. 

 Kalmia latifolia, Linnaeus. 



FAMn-y AND GENUS DESCBIPTION— The Ucath family. Ericaceae, embraces species which 

 are amongst our best known and most popular shrubs. The Huckleberries, Blueberries, Cran- 

 berries, Azaleas, Kalmias. and Rhododendrons are some of the commonest representatives. 

 \ery few representatives ate of any special economic value on account of the wood which 

 they produce. Some are important on account of their aesthetic value, while others yield 

 valuable food or are used In medicine. This family comprises about 90 genera with more 

 than 1.400 species, of which number about 40 genera are found in the United States. 7 of which 

 have tree reptetentatives. The Uora of Penns.vlvania comprises 27 genera with about 43 species. 

 Since most of them are shrubs only 3 species i irpresenting 3 genera are described here. The 

 genera here described are Kalmia, Khododendron, and Oiydendtum. 



The genus Kalmia comprises 5 or species in .North America and Cuba. The species 

 described on tliis page is the only one ivhich reaches tree-size. Two other sUrub species. Sheep 

 Laurel (Kalmia angustifoUa L.) and Swamp Laurel (Kalmia polifolia Wang.), are also 

 native to this State. The genus is named after Peter Kalm, a Swedish naturalist, who 

 traveled in North America during the middle of the ISth century. 



FORM— In Pennsylvania usually a shrub 510 ft. In height with a stout stem which is 

 usually forked, often inclined and bearing divergent branches which form a round compact 

 head. In the South it reaches, a height of 30-40 ft. V'th » diameter of 20 inches. 



EABK — Very thin, reddish-biown, furrowed, peels off into long, narrow, thin scales ex- 

 posing cinnamon-red Inner bark. 



TWIGS — At first leddish-green covered with uscld hairs, later becoming decidedly green, and 

 Bnall.v bro>vn. liather smooth except where roughened by leaf-scars .ind bud scale scars. 



BUDS — Alternate, ovate, sharp-pointed, greenish in color. Leaf-buds are formed early and 

 appear below the clustered flower-buds. Flower-buds are covered by numerous, downy and over- 

 lapping green scales which arc coated with glandular hairs and enlarge with the developing 

 shoot in spring. 



LEAVES — Alternate, sometimes paired, simple, oblong. wedge-shaped at base, entire- 

 margined, acute at apex sometimes tipped with bristle point, 3-4 Inches long, about 5 of an inch 

 wide. Mature leaves are thick, leathery, dark green, glossy above, yellowish-green below, 

 and persist for two seasons, 



LEAF-SCABS— Large, imbedded in twig, witii a cluster of bundle-scars. 



FLOWERS — Emerge from flower buds which begin to expand in early spring and open about 

 May or June. Flowers are borne on red or groea scurfy stalks and arranged in dense many- 

 flowered corymbs which have a diameter of about 4 inches. Calyx is divided into Ave parts. 

 Corolla is white to rose-colored and viscid pubescent. 



FRUIT — Matures about September. It is a ciany-seeded woody capsule, roundish in outline 

 but slightly flve-lobed and covered with Tiscid hairs. Both style and calyx persist. Each 

 capsule produces many seeds. 



WOOD — Diffuse^porous ; heavy, hard, strong, rather brittle. Heartwood redddsh-brown, 

 sapwood lighter colored. Weighs 44.02 lbs. per cubic foot. Where it grows to a fair size 

 it is an excellent wood for fuel. It is also used in manufacture of tool handles, penholders, 

 bucket handles, turnery, and tobacco pipes. About 85,000 lbs. of this wood are produced 

 auuually in North Carolina foi pipes. 



DISTINGUISHING CHAEACTEBISTICS — The Mountain Laurel, also known as Kalmia and 

 Calico-Bush, is one of our few broad-leaved species whose leaves persist over winter. It can 

 be distinguished from all other species native to this State by its thick leathery leaves which 

 are 3-4 inches long, persistent, decidedly flossy on upper surface and yellowish-green on 

 lower surface. The Great Laurel or Rhododendron is also evergreen but its leaves and buds are 

 much larger than those of the Mountain Laurel. The leaves of the Mountain Laurel are 

 shorter, nai rower, and sharpci -pointed than tnose of the Khododendron. 



RANGE — New Brunswick south generally along the mountains to Florida, west to Arkansas. 



DISTRIBUTION IN PENNSYLVANIA— Th.-jughont the State. Most common in the moun- 

 tainous parts, where it often forms almost impenetrable thickets. 



HABITAT — Common along margins of swamps and as an understory in deciduous (forests. 

 Also found on hillsides and hilltops. Very common on rocky and round hilltops. 



IMPORTANCE OF THE SPECIES — The Mountain Laurel remains too small in this State 

 to be of commercial importance on account of the wood which it produces. Next to Khodo- 

 dendron, it is the most attractive native shrub found in our flora. It is a favorite with lovers 

 of the woods who admire not only its blossoms, brt also its leaves and its habit of growth. 



