Note 28 — PART III. MISCELLANEOUS MATTER CONNECTED WITH NAVAL TIMBER.

Laburnum (Cytisus) is the most valuable timber this country produces. It is equally deep in colour, and takes as fine a polish as rose-wood, having also something slightly pellucid in the polished surface. From its extreme hardness, it is much better adapted for use than mahogany, not being indented or injured by blows or rough treatment. We are acquainted with no other timber of home produce so little liable to decay. The large-leaved variety in rich warm soils acquires a diameter of a foot or a foot and a-half, and grows rapidly till it fall into seed-bearing. Its usual very stunted growth is partly owing to less valuable faster growing trees overtopping it: Were it planted alone, and trained to proper curve, it might be profitably reared for the upper timbers (the part where decay commences) of small vessels: it has the thinnest covering of sap wood of any of our timber trees. The extreme beauty and richness of its clustered depending blossoms is a considerable injury to its growth, as it is often broken and despoiled of the branches on this account. The small-leaved Laburnum, though producing the most beautiful timber, is of such puny growth as not to rank as a forest tree. There is a peculiarity, at least seldom occurring in other trees, attending the growth of the small-leaved variety: a branch frequently gives up feeding the connected trunk and roots, drawing supply of nourishment from these upward, without returning much or any of the digested matter downward. This branch above the place of the stagnation of the bark vessels becomes enlarged, running into numerous shoots, which are generally unnaturally thick and unhealthy, approaching to dropsical—often, however, beautifully pendant down to the ground, from their weight and the smallness of the supporting branch. We do not know whether this is an awkward effort towards increase—that these branches, under the influence of a not entirely matured instinct or faculty, droop in search of earth to root, and extend by layers, in conformity to a habit of some tribes of trees, in which this mode of increase is efficient, or that it is a disease unconnected with design or final cause. These overgrown branches of the small-leaved laburnum are generally thrown out by trees, which, owing to circumstances, are little disposed to seeding.