Dove Tree or Davidia. Where reliably hardy (a specimen at Arnold Arboretum, Boston, blooms periodically), an unusual tree, with large white bracts among heart-shaped leaves in spring. Requires special care, but is worth the effort.

Franklinia or Gordonia. Like the dove tree, also requiring special attention. Single, camellia-like, cream-white flowers open in late summer and continue until frost. Leaves are colorful in fall. Barely surviving winters around Boston, this is reliably hardy from New York City southward.

Fringe Tree. Large shrub or small tree, with fluffy, white flowers appearing with unfolding foliage in late spring. Shows up strikingly against evergreens.

Ginkgo. One of the best, very hardy and slow growing with a fascinating form. Also called maidenhair tree, it transplants easily. A fastigiate variation, the Sentry Gingko, will give accent.

Golden-Chain Tree or Laburnum. Small ornamental tree with pendulous, wisteria-like, golden flowers in spring. It will attract much attention in a large plant box.

Golden-Rain Tree or Koelreuteria. One of few yellow-flowering trees for the North. Compound leaves are high¬lighted by upright panicles in midsummer, followed by pods that change through several colors. Golden rain withstands drought.

Hawthorns. Many kinds, with showy red, pink, or white flowers in spring. Outstanding is the English hawthorn, including the red Paul's Scarlet and Arnold hawthorn with white flower clusters. Washington thorn has bright red berries in fall.

Hollies. Pyramidal broad-leaved evergreens with hand¬some foliage and sparkling red berries. American holly is hardier than English, but both have forms with varie¬gated leaves and yellow or orange berries.

All withstand formal clipping. Japanese Red Maple. Dainty, with divided dark leaves and a horizontal habit. Varieties have deep-cut green leaves (Acer palmatum dissectum) or purple foliage (A. p. atropurpureum). Much grown in containers on the West Coast.

Japanese Snowbell or Styrax. Small and spreading, with myriads of exquisite white bells in early summer hanging from underneath the horizontal branches.

Japanese Tree Lilac. The last of the lilacs to bloom, with large, fragrant, cream-white tresses in early summer. Very hardy and slow growing, it can be trained with one or several trunks.

Magnolias. Many kinds with showy flowers. Earliest to bloom is the star magnolia in white or pink. If spring frost threatens, move to shelter during night. Next to flower is the common saucer magnolia in white, pink, rose, or purple. This has an interesting habit and soft gray bark. Sweet bay magnolia produces fragrant, cream-white flowers over a period of weeks during the summer. Attractive dark green leaves are whitish beneath.

Moraine Locust. Recently introduced variety, with fine compound leaves and an open, graceful habit. Fast grow¬ing, and pest-free with neither thorns nor messy seed pods. Sunburst locust, another variety, is noted for its golden-yellow tips.

Mountain Ash. Showiest is the European with a loose habit and white flowers in spring followed by rich clus¬ters of orange-red fruits. Fast-growing plants offer filtered shade.

Oriental Flowering Cherries. Small trees, with single or double, pink, rose, or white flowers in spring. Unique is the weeping cherry, with very early pink blossoms. Variety Kwanzan, a narrow, upright grower, has large double blooms resembling roses.

Pines. Choice depends on climate and personal preference. The red, pitch, Scotch, Austrian, and Japanese black pines are seashore subjects, but all pines take well to container culture if kept moist and not neglected in winter. They do best in sun and can be pruned or sheared.

Poplars. Fast-growing, weak-wooded trees, easily replaced because they are readily obtainable at reasonable prices. The slender Lombardy poplar can be planted for accent or a hedge. All easy for the container garden.

Redbud or Judas Tree. Small, with rose-pink flowers in tight clusters and heart-shaped leaves. The eastern common redbud is the hardiest, but in milder climates the Chinese redbud is equally lovely.

Russian Olive. Admired for silvery leaves and the crooked trunk and branches it develops. Very hardy and vigorous, fine for the seashore because it withstands wind and salt spray.

Silverbell or Halesia. Upright tree with tiny bells in white or pink at dogwood and tulip time. Locate where it can be observed closely.

Scholar Tree or Sophora. A member of the pea family, with compound leaves and cream-white flowers in midsummer. Tolerates dust and soot of cities.

Sourwood or Oxydendrum. Small summer-flowering tree, with drooping clusters of small, fragrant flowers and lustrous leaves that turn scarlet in autumn. In containers, specimens can easily be provided with the acid soil they need.