﻿Trees of New York State 323 



ERICACEAE 



Kalmia latifolia L. 



Mountain Laurel 



Habit — Generally a shrub 5-20 feet in height with a stem 1-6 inches in 

 diameter, farther south at its optimum range occasionally 30-40 feet in 

 height vrith a trunk 18-20 inches through. Trunk short, stout, often 

 oblique, usually forking into a number of divergent branches which form 

 a compact, round-topped cro'rni. 



Iieaves — Alternate or occasionally opposite or in whorls of 3, persistent, 

 oblong or elliptic-lanceolate, 3-4 inches long, acute and sometimes bristle- 

 tipped at the apex, euneate at the base, entire, at maturity thick, coria- 

 ceous, dark green and rather dull above, yellowish green and paler below, 

 borne on stout petioles about % of an inch in length, falling during 

 their second summer. 



Flowers — Appearing in May and Jime from separate flower-buds formed the 

 previous summer, showy, perfect, borne on red or green scurfy pedicels 

 in terminal, compound, many-flowered corymbs about 4 inches in diameter. 

 Calyx di^•ided nearly to the base into 5 narrow, acute, green lobes which 

 persist in fruit. Corolla white or rose-colored, rotate, with 10 pouches 

 below the 5-parted limb. Limb divided into 5 ovate, acute lobes. Stamens 

 10, hypogynous, shorter than the corolla, with filiform filaments and 

 oblong anthers. Prior to anthesis the anthers are held in the corolla- 

 pouches. At anthesis the "bowed" filaments straighten elastieally, rais- 

 ing the anthers aloft and catapulting the poUen from terminal pores. 



Fruit — A globose, glandular-hispid, slightly 5-angled and 5-celled, woody 

 capsule, about 3/16 of an inch in dianiter, crowned by the persistent 

 style and subtended at the base by the persistent calyx, maturing in 

 September and October. At maturity the capsule splits septieidally into 

 5 carpels which separate from the persistent central axis and open down 

 the inner side by a narrow suture. Mature capsules persist on the plant 

 until the following year. Seeds oblong, numerous, minute, winged. 



Winter characters — Twigs reddish green and lustrous, becoming bright red- 

 dish brown the second year. T^vig-tips often winter kiUing. Leaf-buds 

 ovate, small, acute, axillary. Flower-buds clustered above the leaf-bud, 

 stouter, covered by numerous, glandular-pubescent scales. Mature bark 

 thin, reddish brown, dissected by longitudinal fissures into narrow ridges 

 which flake into long scales at the surface. 



Habitat — At the northern limits of its range, mainly confined to low. rich 

 bottom-lands, farther south thriving on rich, rocky hillsides, often ascend- 

 ing to elevations of several thousand feet and covering extensive tracts 

 in deciduous forests with a dense, almost impenetrable thicket. 



Kange — New Brunswick westward through southern Ontario and Ohio, 

 southward along the mountains into the Gulf States. Zones A and B. 



Uses — One of the most attractive shrubs of the eastern United States, 

 especially when it is covered with showy clusters of white or pink blos- 

 soms. It is easily raised from seed and may be readily transplanted. It 

 Avill not thrive on limestone soils. The addition of leaf-mold as a top 

 dressing to the soil is recommended. Hardy in shady or open situations 

 in central and southern New York. 



