The herb orache was formerly cultivated as a kind of summer spinach; but in this country it has long been expelled from the kitchen garden by other kinds. It is, however, still seen in the gardens of France, where it is commonly called Arroche des jardins, being used in that country, both by itself as a spinach, and mixed with sorrel, the acidity of which it corrects. Seven varieties are described, which do not differ in their qualities, but are distinguished by the colour of their foliage.
XIII. On planting the moist Alluvial Banks of Rivers with Fruit-Trees. By Mr. John Robertson. [◊]
The object of this writer is to show that the low grounds that form the banks of rivers are, of all others, the best adapted for the growth of fruit trees; the alluvial soil of which they are composed, being an intermixture of the richest and most soluble parts of the neighbouring lands, with a portion of animal and vegetable matter, affording an inexhaustible fund of nourishment. In such situations, however, the trees are liable to injury from floods in the winter, unless some means are used of draining off the stagnant water. This is to be effected by digging deep trenches between the rows of trees, casting up the earth from the trenches around the trees on either side, so as to form elevated banks. Such is the practice in Holland, where the western slopes of the dykes are generally covered with fruit-trees, chiefly apples and pears. Mr. Robertson is of opinion, that the banks should be raised, if possible, at least three or four feet above the highest water-mark, and be made eighteen feet broad at the base, and twelve at top; the trenches should be fifteen or sixteen feet wide, admitting the soil to be three or four feet deep.
Upon this plan, it is probable that abundant crops would be obtained; but with regard to the quality of the produce, we suspect it will be quite as indifferent as the apples and pears of the Dutch, which are notorious for their want of flavour.
XIV. On Dahlias. By Mr. William Smith. [◊]
This is an attempt to distinguish by words the best varieties of the Dahlia, and to fix the names of those which are the most worthy of cultivation. Sixty kinds are well described, [p171] arranged in divisions depending upon the size of the plants and the colour of their flowers. We do not propose to analyze this paper, which is far too extensive for our limits; but instead, to throw together a few remarks which are suggested by the subject.
The first fact to which we would call attention has reference to acclimatization. The Dahlia has now been cultivated in Europe with the utmost assiduity for nearly thirty years. During that period millions of plants have been raised from seeds, and under almost every possible variation of climate; and anomalies the most singular, not only in colour, but in general constitution and physiological structure, have been obtained. The colour of the flower has been altered from pale yellow, or lilac, to every hue of red, purple, or yellow, to pure scarlet and to deepest morone, or has even been wholly discharged from the radial florets in the white varieties; the period of flowering has been accelerated nearly two months; the tall rank weed, exceeding the human standard in height, has been reduced to a trim bush, emulating the pæony in dwarfishness; the yellow inconspicuous florets of the disk have been expelled to make room for the showy deep-coloured florets of the ray; what is more remarkable still, the same yellow inconspicuous florets of the disk have been enlarged, and stained with rich morone, so as to rival the colours of the ray without losing their own peculiarity of form; and finally, the whole foliage and bearing of the plant has been altered by the substitution of simple leaves for compound ones. But notwithstanding all this proneness to change, notwithstanding the multitude of varieties which have been thus procured by seed, not one individual has yet been discovered, in any degree whatever, more hardy than its ancestors. The earliest frosts destroyed the Dahlias as certainly in 1826, as they could have done in 1789.
But, however strong may be the disposition of the Dahlia to vary from its original structure, it is curious to observe how strictly it conforms to the laws by which such variations are controlled by nature. In altered structure all the changes take place from circumference to centre. The florets of the ray displace those of the disk, but the latter never attempt to occupy the ray; when a change occurs among the florets of the disk, they merely dilate and assume the colour of the ray, without changing their position or their peculiar form. So with the leaves; by a reduction of the lateral leaflet, till the terminal one only remains, simple foliage is substituted for that which was compound: but no case has been found in [p172] which the suppression of the terminal leaflet has taken place and the lateral ones have been preserved. In change of colour, too, there is a circumstance which demands consideration, and of which no explanation has yet been offered. It is not generally known, although long ago noticed by M. De Candolle, that among flowers, yellows will not produce blues, nor blues yellows, although both these primitive colours will sport into almost every other hue. Thus the hyacinth, the natural colour of which is blue, will not produce a yellow, for the dull, half-green flowers called yellow hyacinths, are, in our judgment, whites approaching green; the blue crocus will not vary into yellow, nor the yellow into blue; and the ranunculus and the dahlia, the natural colour of both which, notwithstanding the popular belief to the contrary, with respect to the dahlia, is, we believe, yellow, although they are the most sportive of all the flowers of the gardens, varying from pink to scarlet, and deepest shades of purple, have never yet been seen to exhibit any disposition to become blue. This subject offers a most amusing field for investigation, and would well repay the attentive consideration of the philosopher.
XV. On the Cultivation of Camellias in an open Border. By Mr. Joseph Harrison. [◊]
Mr. H. finds that the double red camellia, the double white, and the double striped, will bear an English winter if planted out when about two feet high, having been previously stunted in their growth by repeatedly stopping their leading shoots. For two winters the young plants are to be protected by a wooden screen fixed round them, and covered by a hand-glass, the whole being enveloped in mats; afterwards they require no other protection than to be guarded from heavy snowstorms, and to be assisted by a thick covering of old tan upon the ground in which they grow, to the distance of two or three feet from their stems. If this success has been met with in Yorkshire, what may not be expected in our more southern counties! On the 12th of March of the present year these camellias were not injured by a frost which did considerable damage to the common laurel.