Hardy North American trees which are most ornamental in their elegant habit and attractive pinnate leaves. Pink or white pea-shaped flowers are produced in summer. They thrive on all soils and are particularly valuable in dry, sunny positions, sheltered from wind. If grown in lush or exposed circumstances, their brittle branches are liable to break in gales. Many of the smaller forms are successful in town gardens.
Robinia ambigua decaisneana ( pseudo-acacia decaisneuna) becomes a handsome, medium-sized tree; the large racemes of pale pink flowers are very conspicuous. R. l’ertilis Monument is a small tree of narrow upright growth also bearing pale pink flowers.
A graceful and elegant tree for the small garden, R. hillieri ( kelseyi x pseudoacacia ) has lilac-pink flowers which are produced at mid-summer The common or false acacia, R. pseudoacacia, is a large picturesque suckering tree with spiny twigs, naturalized in parts of Europe; its white flowers are produced in early or midsummer. It is best represented in gardens by one of its varieties which are generally small or medium-sized trees of more compact habit. The best of these includes Frisia, a small or medium-sized tree of recent introduction and one of the most striking of foliage trees available today. Its bright golden-yellow leaves maintain their colour from spring to autumn. It is most effective when associated with purple-leaved trees or shrubs. The variety inermis, the mop-head acacia, is a small, round-headed tree, formed by a dense mass of spineless branches and deep green pinnate leaves. It is a popular tree for street or public planting, particularly in France.