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136 Leguminous plant, and its flowers greatly resemble those of the pea. They are white, sweet-scented, and gathered into a long, pendulous raceme, like that of the laburnum: May and June. The tree is sensitive, and on a branch being touched the leaves will all incline towards the branch, whilst each leaflet advances half-way towards its opposite fellow. The same movements occur at sunset, the leaflets then remaining folded face to face until dawn. The fruit (shown in figure) is that form of pod called a lomentum, in which the valves are constricted between the seeds.

The genus is named in honour of Jean Robin, a French botanist, whose son cultivated the first specimens of R. pseudacacia in Europe.

One of the most pleasing in growth of our forest trees is the Ash, its grey trunk rising to eighty or a hundred feet, and its sweeping branches, the lower ones bending upwards at the tips, clothed with the gracefully curving long pinnate leaves. The character of these compound leaves and their leaflets is well shown in our illustration, together with two clusters of the winged fruits.

The Ash is a native of Britain, although most of the specimens we meet in woods and plantations have been reared in a nursery and planted out. There are many cultivated varieties of F. excelsior; and a large number of species have been introduced during the present and last centuries, chiefly from S. Europe and N. America. Ash and Privet are the only native representatives of the order Oleaceæ, to which the Olive belongs. It cannot be said that Fraxinus excelsior is a typical representative of the order, since most species included in it bear flowers composed of all the floral organs, whereas excelsior has neither calyx nor corolla. Its flowers appear in