Some writers say that the roots of trees do not descend below the level to which the sun’s heat is able to penetrate; which, of course, depends upon the nature of the soil, whether it happens to be thin or dense. This, however, I look upon[2548] as a mistake: and, in fact, we find it stated by some authors that a fir was transplanted, the roots of which had penetrated eight cubits in depth, and even then the whole of it was not dug up, it being torn asunder.[2549] The citrus has a root that goes the very deepest of all, and is of great extent; next after it come the plane, the robur, and the various glandiferous trees. In some trees, the laurel for instance, the roots are more tenacious of life the nearer they are to the surface: hence, when the trunk withers, it is cut down, and the tree shoots again with redoubled vigour. Some think that the shorter the roots are, the more rapidly the tree decays; a supposition which is plainly contradicted by the fig, the root of which is among the very largest, while the tree becomes aged at a remarkably early period. I regard also as incorrect what some authors have stated, as to the roots of trees diminishing[2550] when they are old; for I once saw an ancient oak, uprooted by a storm, the roots of which covered a jugerum of ground.
CHAP. 57.—TREES WHICH HAVE GROWN SPONTANEOUSLY FROM THE GROUND.
It is a not uncommon thing for trees when uprooted to receive new strength when replanted, the earth about their roots forming a sort of cicatrix[2551] there. This is particularly the case with the plane, which, from the density of its branches, presents a remarkably broad surface to the wind: when this happens, the branches are cut off, and the tree, thus lightened, is replaced in its furrow: this, too, has also been done before now with the walnut, the olive, and many others.
(32.) We have many instances cited also of trees falling to the ground without there being any storm or other perceptible cause, but merely by way of portentous omen, and then rising again of themselves. A prodigy of this nature happened to the citizens of Rome during their wars with the Cimbri: at Nuceria, in the grove consecrated to Juno, an elm inclined to such a degree, even after the top had been cut off, as to overhang the altar there, but it afterwards recovered itself to such an extent as to blossom immediately: it was from that very moment, too, that the majesty of the Roman people began to flourish once again after it had been laid low by disaster and defeat. A similar circumstance is said to have taken place also at Philippi, where a willow, which had fallen down, and the top of which had been taken off, rose again; and at Stagira, in the Museum[2552] there, where the same thing occurred to a white poplar; all which events were looked upon as favourable omens. But what is most wonderful of all, is the fact that a plane, at Antandros, resumed its original position even after its sides had been rough-hewn all round with the adze,[2553] and took root again: it was a tree fifteen cubits long, and four ulnæ in thickness.
CHAP. 58.—HOW TREES GROW SPONTANEOUSLY—DIVERSITIES IN THEIR NATURE, THE SAME TREES NOT GROWING EVERYWHERE.
The trees which we owe to Nature are produced in three different ways; spontaneously, by seed sown, or by a slip which throws out a root. Art has multiplied the methods of reproduction, as we shall have occasion to state in its own appropriate Book:[2554] at present our sole subject is the operations of Nature, and the manifold and marvellous methods she adopts. The trees, as we have already stated,[2555] do not all of them grow in every locality, nor will they live, many of them,[2556] when transplanted: this happens sometimes through a natural antipathy on the part of the tree, sometimes through an innate stubbornness, but more frequently through the weakness of the variety so transplanted, either the climate being unfavourable, or the soil repulsive to it.
CHAP. 59.—PLANTS THAT WILL NOT GROW IN CERTAIN PLACES.
Balsamum[2557] will grow nowhere but [in[2558] Judæa]: and the citron of Assyria refuses to bear fruit in any other country. The palm, too, will not grow everywhere, and even if it does grow in some places, it will not bear: sometimes, indeed, it may make a show and promise of bearing, but even then its fruit comes to nothing, it seeming to have borne them thus far in spite of itself. The cinnamon[2559] shrub has not sufficient strength to acclimatize itself in the countries that lie in the vicinity of Syria. Amomum,[2560] too, and nard,[2561] those most delicate of perfumes, will not endure the carriage from India to Arabia, nor yet conveyance by sea; indeed, King Seleucus did make the attempt, but in vain. But what is more particularly wonderful, is the fact that most of the trees by care may be prevailed upon to live when transplanted; for sometimes the soil may be so managed as to nourish the foreigner and give support to the stranger plant; climate, however, can never be changed. The pepper-tree[2562] will live in Italy, and cassia[2563] in the northern climates even, while the incense-tree[2564] has been known to live in Lydia: but how are we to impart to these productions the requisite warmth of the sun, in order to make all the crude juices go off by evaporation, and ripen the resins that distil from them?
Nearly as great a marvel, too, is the fact that the nature of the tree may be modified by circumstances, and yet the tree itself be none the less vigorous in its growth. Nature originally gave the cedar[2565] to localities of burning heat, and yet we find it growing in the mountains of Lycia and Phrygia. She made the laurel, too, averse to cold, and yet there is no tree that grows in greater abundance on Mount Olympus. At the city of Panticapæum, in the vicinity of the Cimmerian Bosporus, King Mithridates and the inhabitants of the place used every possible endeavour, with a view to certain religious ceremonies, to cultivate the myrtle[2566] and the laurel: they could not succeed, however, although trees abound there which require a hot climate, such as the pomegranate and the fig, as well as apples and pears of the most approved quality. In the same country, too, the trees that belong to the colder climates, such as the pine, the fir, and the pitch-tree, refuse to grow. But why go search for instances in Pontus? In the vicinity of Rome itself it is only with the greatest difficulty[2567] that the cherry and the chesnut will grow, and the peach-tree, too, at Tusculum: the Greek nut, too, is grown there from grafts only at a cost of considerable labour, while Tarracina abounds with whole woods of it.