The enormous natural order of LeguminosÆ or pea-flowered plants contains many of the loveliest flowering plants in the world, but among them there are but three which, attaining the stature of trees, contribute importantly to the beauty of British woodlands—namely, the common laburnum, the alpine laburnum, and the false acacia or locust tree.

Every country child knows the laburnum, but it is not every planter who recognises that there are two distinct species, bearing a general resemblance to each other, but differing in the time of flowering and in other important respects. The species most usually planted is the common laburnum (L. vulgare), and of a truth it would be difficult to name any tree more delectable with its "dropping wells of fire." It is uncertain how early it was brought from Central Europe to Great Britain; Tradescant had it growing in 1596; but if "awburne," mentioned in an Irish Act of Edward IV. (cap. iv., 1464) among the four woods prescribed for the bow with which every Englishman in Ireland was to provide himself, means "laburnum," it follows that this tree must have been in cultivation from very early times. Indeed, the botanist Matthiolus mentions it as being better even than the yew for bow-making; and we may recognise the word "awburne" in the old Lowland Scots name for the laburnum, "hoburn saugh," both being from the alternative Latin form, alburnus. Gerard called it the bean-trefoil.

There is but one precaution to be observed in planting laburnums—namely, that they should not be within reach of horses or cattle, for the seeds contain a powerful poison called cytisine. Some years ago, wishing to do wayfarers a service by enlivening a stretch of high road, I caused a row of laburnums to be planted on either side. The trees had attained some stature, when a Clydesdale mare belonging to the tenant of a field bordering the road suddenly died, her death being attributed to eating laburnum seeds, so the trees had to be uprooted. Neither leaves nor bark appear to contain the poison, judging from the avidity shown by rabbits in devouring them. No tree is so vulnerable at all ages by those detestable creatures as are the laburnum and the holly. The largest stems are liable to be barked by them in hard weather. Some writers have copied Pliny in stating that bees will not visit the flowers of laburnum; but Pliny cannot have been writing from personal observation, for modern bees, at least, show no aversion to the yellow blossoms.

The common laburnum seldom exceeds 30 feet in height. The largest I have seen stands in the laundry yard of Alnwick Castle, over 40 feet high, wide-spreading, with a double stem measuring over 11 feet in girth near the ground. When Loudon measured it in 1835 the girth was only 6 feet 11 inches. It is a magnificent sight when in bloom. The timber of laburnum, though now greatly neglected in favour of foreign woods, is of admirable quality for cabinet work, being of a dark olive tint, and taking a fine polish. Seeing that the laburnum is perfectly hardy in our climate and grows rapidly in any well-drained soil, it seems a pity that the fine material it produces is not more commonly used.

The alpine laburnum (L. alpinum) goes by the name of Scottish laburnum in the nursery trade. Like the common laburnum, it is a native of Central Europe, being, probably, merely the mountain form of the other, to which it bears a strong general resemblance. The readiest means of distinguishing between the two species consists in the foliage and young shoots. In the common laburnum the leaf stalks, young shoots, and under sides of the leaves are thickly clothed with a smooth, silky pubescence, whereas in the alpine species these parts are quite bare, which causes the tree when in leaf to appear of a deeper green than the other. But the important difference for planters is that the alpine laburnum blossoms a fortnight or so later than the common laburnum, thereby prolonging the display of these charming trees. Elwes describes the flowers of the alpine laburnum as being paler in colour than those of the other species; but according to my own observation they are of the richer gold. There are some fine specimens in the Edinburgh Botanic Garden, verging upon 100 years old, about 40 feet high, and now past their prime. The timber is of the same fine quality as that of the common laburnum.

Some beautiful hybrids have been reared between these two species, and planters cannot be too strongly recommended to use them. The variety known as L. watereri bears flower-tassels 15 to 18 inches long. As it is propagated by grafting on the common species, care should be taken not to allow the stock to overcome the scion, root suckers and stem spray being rigidly suppressed.

Another curious hybrid is L. adami, which originated nearly a hundred years ago in a French nursery through engrafting Cytisus purpureus on a laburnum stem, with the result that this graft-hybrid produces yellow flowers on some branches and violet ones on others.

Mr. Gerald Loder has secured a charming effect at Wakehurst Place, Sussex, by planting wistaria to grow with laburnum, the flower racemes being similar in size and shape, but respectively of the complementary colours, yellow and violet.

In writing of a beautiful tree as the false Acacia, no reflection upon its integrity is implied in the epithet. The Robinia is so called because Englishmen have chosen to call it an acacia, which it is not, any more than it is a locust tree, as the Americans speak of it. Its scientific title is Robinia pseudacacia, commemorating Jean Robin, who first reared it in France in 1601 from seeds sent to him from North America, where it is very widely spread and much valued for the durability of its timber.

William Cobbett (1762-1835) conceived an extravagant idea of its merits, and predicted that it would supersede all British trees, including the oak; but this expectation has fallen far short of fulfilment. Among many other landowners who were induced to act on the faith of it, Lord Folkestone, a fellow-Radical of Cobbett's, planted 13,000 or 14,000 locusts at Coleshill Park, Berkshire, in 1824; but of these only very few remain now, none of them over 60 feet high. The fact is, the Robinia loves more sun than it gets in most parts of our islands and a hotter soil. This renders it unsuitable for planting in Scotland, especially in the humid west. There are, indeed, a few large specimens north of the Tweed, such as one at Cordale House, Dumbartonshire, 64 feet high by 7 feet in girth; another at Mauldslie Castle, Lanarkshire, 60 feet high by 8 feet 7 inches in girth; and, most northerly of all, one at Gordon Castle, which in 1904 measured 56 feet high by 9 feet in girth. But, as a rule, it is only to be found in good form in the sunnier shires; besides, notwithstanding the strength of its timber when felled, the growing boughs are exceedingly brittle, which makes the tree unsuitable for exposure to high winds.

On the sandy soil of parts of Surrey, especially about St. George's Hill, the locust thrives well, reproducing itself freely from self-sown seed, and forming very lovely objects when covered with fragrant white blossoms in June. Even in such parts of England where it does best, it is not profitable to let it stand longer than, say, twenty or thirty years, when it makes admirable fencing and gate-posts, which are almost imperishable. At a greater age the trunk becomes coarse and deeply furrowed, often becoming rotten towards the centre. Elwes mentions a locust tree at Frogmore, near Windsor, as the largest in Britain, which he found in 1908 to be 88 feet high by 14 feet 7 inches in girth. One about the same height at Bowood, Lord Lansdowne's place in Wiltshire, was slightly taller, but girthed only 8½ feet.

In France and Italy the locusts thrive as vigorously as in their native continent, and are exceedingly beautiful during the flowering season. They also make very effective hedges, being regularly cut over, when they send up long and strong shoots armed with murderous thorns.

Few trees stand the drought, heat, and smoke of London as well as the Robinia, which carries its verdure unchanged long after the limes and elms have become seared and unsightly. Many a time, when Parliament continued sitting through and after the dog days, have I refreshed my eyes by gazing upon a fine Robinia which stood at the corner of the late Lord Sefton's house in Belgrave Square. But that tree is no more, for, when the house changed hands after its former owner's death, and was put into the hands of builders and decorators, they felled my friendly Robinia.

There are three species of Robinia seldom planted in this country—namely, R. hispida, R. neo-mexicana, and R. viscosa, all with beautiful pink or rose-coloured flowers. Of these, the first-named, a native of Carolina, is the most desirable, but it is even more brittle than the locust or false acacia. Its blossoms are so exquisite as to entitle the tree to the advantage of being trained on a wall.

There are two other trees of the peaflower order which one would fain see more frequently planted in the sunnier districts of Great Britain, namely the Judas tree (Cercis siliquastrum) and the white-flowered Sophora (S. japonica). I happen to be writing within a couple of hundred yards of the finest Judas tree known to me—at Twyford Lodge, near Winchester. It is 35 feet high, and in these early days of May presents a sight which cannot easily be forgotten. The branches, still leafless, are thickly set with blossom; flowers even break out from the old bark on the stem, and the effect of the whole is a dome of soft vieux rose (see Frontispiece). It is a native of southern Europe, but agrees perfectly with the climate of England, except in northerly districts which are scant of sun, where it should receive the protection of a wall to encourage the formation of flower buds. The Judas tree (so named from the fond belief that the false Apostle hanged himself thereon) is seldom to be seen in our pleasure-grounds, though it has often been planted there; the reason for this being that it is of slow growth in its early stages, and gets smothered with ranker things, often of less merit.

The Pagoda tree (Sophora japonica) is a native of China, where from immemorial time it has been used in medicine, its flowers, seeds and bark being powerfully purgative. Its blossoms appear in August and September, varying in hue from white to yellow, with a tinge of purple. Those which I have seen bear cream-coloured flowers in long, loose panicles, contrasting finely with the dark, pinnate foliage. The tallest specimens I have seen are at Syon House, about 70 feet high. There is also a very large one within the Tilt Yard of Arundel Castle, and Elwes measured one at Cobham Park, Kent, which was 85 feet high in 1905. At page 144 is shown a fine Pagoda tree in the Botanic Garden at Oxford. I do not remember to have seen any specimens in Scotland. Probably the late flowering habit of the tree would not suit the northern kingdom.