Trees with deciduous, alternate, oblong-lanceolate, pointed, serrate, sour-tasting leaves. Flowers small, in large panicles at the ends of the branches. In summer. Fruit small, dry capsules, with 5 cells and many seeds.
O. arbòreum.
Oxydéndrum arbòreum, DC. (Sorrel-tree. Sourwood.) Leaves in size and shape much like those of Peach trees. Flowers small, urn-shaped. Small-sized tree, 15 to 50 ft. high; wild in rich woods, Pennsylvania and southward, mainly in the mountains. Rare in cultivation, but very beautiful, especially in autumn, when its leaves are brilliantly colored, and the panicles of fruit still remain on the trees. It is perfectly hardy both at the Arnold Arboretum, Boston, and the Missouri Botanical Garden, St. Louis.
Genus 51. KÁLMIA.
Evergreen shrubs with alternate, entire, thick, smooth leaves. Flowers large, beautiful, cup-shaped, in showy clusters. Fruit a small, 5-celled, many-seeded capsule.
K. latifòlia.
Kálmia latifòlia, L. (Mountain-laurel. Calico-bush.) The only species which grows at all tree-like has ovate-lanceolate or elliptical, smooth, petioled leaves, tapering at both ends and green on both sides. Flowers in terminal corymbs, clammy-pubescent, white to pink. June. Pod depressed, glandular. Shrub or small tree, 4 to 25 ft. high, with reddish twigs; wild in rocky hills and damp soils through out; occasionally planted. Wood very hard and close-grained.
Genus 52. RHODODÉNDRON.