This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Kalmia Carolina Small, Fl. SE. U. S. 886. 1903.
Similar to K. angastifolia in habit, but with the foliage, especially the younger parts, copiously fine-pubescent. Leaves oval to oblong, 2/3'-1 3/4' long, 4"-8" wide, obtuse, permanently canescent-tomentulose, at least beneath and paler beneath than above; flowers purplish, 3"-4 1/2" broad, numerous in small corymbs; pedicels very slender, canescent, 3"-6" long; calyx-segments oblong-lanceolate; style finely pubescent; capsules spheroidal, pale-pubescent and glandular, about 2" in diameter.
Kalmia latifolia L. Sp. Pl. 391. 1753.
Kalmia latifolia myrtifolia Rand, Rhodod. 125. 1876.
A shrub with very stiff branches and terete twigs, often forming dense thickets, 3°-20° high, rarely becoming a tree with a maximum height of about 400 and trunk diameter of 18'. Leaves alternate, or some of them opposite, or rarely verticillate in 3's, petioled, glabrous, oval, ovate-lanceolate, or elliptic, usually acute at both ends, rarely narrowly oblong-lanceolate, flat, green on both sides, persistent, 1'-5' long, 1/4'-1 1/2' wide; flowers 9"-12" broad, pink to white, numerous and showy in compound terminal corymbs; pedicels bracted and 2-bracteolate at the base, slender, 1/2'-1 1/2' long, densely glandular, erect, even in fruit; calyx and corolla glandular; capsule depressed-globose, 5-lobed, glandular, 2-3' in diameter; calyx and filiform style long-persistent, the latter falling when the capsule begins to open.
In woods, preferring sandy or rocky soil, New Brunswick to Ontario, Indiana, western Kentucky, Florida and Louisiana. Wood very hard, brown; weight per cubic foot 44 lbs. Clamoun. Spoonwood. Broad-ieaved kalmia. Ivy-bush. Wood- or small laurel. Big-leaved ivy. Spoonhunt. May-June.
K. polifolia Wang. Beob. Ges. Naturf. Freunde Berlin 2:
A glabrous shrub, 6'-2° high, with erect or ascending branches, the twigs 2-edged. Leaves opposite or sometimes in 3's, very nearly sessile, oblong or linear-oblong, mostly obtuse at the apex, narrowed at the base, green above, white-glaucous beneath, ¥-2' long, 2"-6" wide, the margins revolute, often strongly so; flowers in simple umbels terminating the branches, few (1-13), purple, 5"-9" broad; pedicels filiform, 1/2'-1 1/2' long, erect, even in fruit; calyx-segments ovate, scarious-margined, acutish or obtuse, persistent; capsule depressed-globose, glabrous, about 2k" in diameter.