CHAPTER IV.
WATER PLANTS FOR THE AQUARIUM.
How to stock a Tank quickly.—It is usual to fix the plants and fill up the tank to within a few inches of the top, and then leave the whole for a week before completing the collection by the introduction of fishes. Where a beginner has sufficient patience to wait, this is very advisable, because the whole gets well settled, the plants start into growth, and the water gets softened and charged with oxygen. But this plan is not the only one that may be followed, and if well-washed pebbles be used instead of mould, as I have advised, the fishes may be introduced the same day as the plants are inserted, by
CALLITRICHE.
first taking care that you insert plenty of large healthy plants, and then throw on the top as much of the brook starwort—Callitriche autumnalis—as will cover the whole. I lately stocked two tanks in this way, and performed the whole in less than two hours, forming the bottom, planting the vegetation, and adding the fish—perch, tench, Prussian and British carp, roach, minnows, gudgeon, and chub—and all went on as well as if the tank had stood a month to strengthen, the water being from the first moment as brilliant as any of the Castalian springs that flow through classic verses. The lovely green of the starwort, spread over the whole of the surface of the water, has a fairy-like effect. It is necessary to get a good supply of starwort from a brook, throw it into a large vessel of clear water, pick off the green heads, with four or six inches of stem only to each, then wash all these picked portions till they are bright and clean, and throw the whole into the tank to take its chance. You must be lavish as to quantity. It soon spreads over the surface, and arranges itself most beautifully, forming a rich green ceiling, giving the verdant shadow which a new tank wants; it grows freely, lasts for months, continually throwing out new roots and shoots from the joints, and creates abundance of oxygen, from the first hour of its being thrown in. Whenever it seems desirable it can be got rid of by simply lifting it out. My own are the only tanks I have seen stocked in this way.
Selection of Plants.—There is scarcely any aquatic plant but may be grown in an aquarium, and unless some attention is given to the botanical department, only half the pleasure and instruction it is capable of affording is attained. I cannot agree with Mr. Gosse, that the vegetation of a tank has so strictly a secondary place—“preserved because they cannot be dispensed with,”—for in either a marine or fresh-water vessel the vegetation is a special source of beauty and interest, and fairly divides attention with the animals. Supposing it were impossible to keep animals in such vessels, they would still be acceptable for the formation of aquatic gardens.
Beauty of form and adaptability to confinement are the requisites for this purpose, and the more lakes and rivers are explored, the more the botanical department of the aquarium will be extended, both as to ornament and usefulness.
STRATOIDES ALOIDES.
Water Soldier.—Among the plants easily attainable, and which combine grace of outline with cleanliness of growth, and tendency to create oxygen, I can recommend, first of all, the famous water soldier—Stratoides aloides—a lovely cactus-like plant, which grows equally well with or without a root, as indeed most water-plants do. In form it closely resembles the tuft of herbage on the crown of a pine apple, and its leaves have similar serrated edges. If thrown in, it floats on the surface, and puts forth new heads in plenty, each new head springing from the base of a leaf on a long stalk. By separating these when pretty well grown, and removing the stem from the base, any number of new plants may be formed. If it be wanted to root at the bottom (as indeed is best) cut away the decayed portion of the base, and trim off every dark-coloured leaf and throw the plant in again. In a few weeks it will throw out roots, and it may then be attached to a stone
VALLISNERIA SPIRALIS.
by a piece of bass, and dropped in to fix itself where wanted, without in any way disturbing the tank.
Starwort I have already spoken of, as a good purveyor of oxygen. It is a pretty plant of a delicate green hue, which appears on the surface of brooks and ditches everywhere, both in this country and all over the continent. At a little distance it has so much the appearance of duckweed as to be recognised with difficulty. Its old botanical name is Callitriche aquatalis, but owing to its liability to vary its appearance, botanists have lately divided it into several species, the two most common of which are C. autumnalis, and C. Vernalis.
Vallisneria spiralis is essential to every fresh-water tank. It is a native of Italy, and is named in honour of the Italian naturalist, Vallisneria. The blooming of this plant is very curious and worthy of close scrutiny. It likes abundance of light, and must be grown as a bottom plant, flourishing only when well rooted.
Anacharis alsinastrum, or the New Water-weed, is an interesting plant that grows freely, whether rooted or not; but it can only be considered ornamental when springing from the bottom. It thrives just as well without a root as with one, but, if firmly fixed, usually sends down a number of white rootlets from joints on the stem. I have seen roots of this kind sent down six inches to reach the bottom, while the lower part of the stem was decaying rapidly.
Myriophyllum contributes some lovely members to the aquarium. All the plants of this genera are of elegant structure, the leaves finely divided and of a delicate emerald green. M. Spicatum is perhaps the best, but there are other species to be had of the dealers that are worthy of attention.
Potamogeton is an extensive genera of water-plants, numbering not less than fifteen species in the brooks and rivers of this country alone. P. fluitans, crispus, and densus, are most easily obtained, and they flourish in the tank, and make rich branching masses for the centre, or to climb over rockwork. They are all rather coarse and apt to shed their lower leaves, but, if well placed, produce a striking effect. They blossom freely in the aquarium, and that is a great recommendation.
MYRIOPHYLLUM SPICATUM.
Nuphar lutea is the best of the water-lilies for the purpose: it grows freely and produces graceful outlines below and above. It should be planted early in spring to secure blossom; but if it does not throw up blossoms in summer it may be removed, and its place supplied by a plant in full bloom. Nymphæa macrantha and Nodorata minor are also highly suitable.
Ericaulon, or the pipewort, sends its only English species—E. septangulare—to the tank. It is a bog plant, rises six inches high, and does not succeed if immersed more than three inches; hence it is suitable for the top of an arch, but not for the deep water of the tank. The plant is perennial and produces a white blossom, with one petal and four stamens. The flower-stem is velvety, and the leaves spread in a tuft from the root.
POTAMOGETON DENSUS.
Utricularia Vulgaris, or the hooded milfoil, may be recommended as a botanical curiosity, but is met with only (as far I know) in the brooks of the southern counties—Hants and Surrey especially. It produces a yellow blossom in June and July. The root has a curious inflated appendage. There are two other species, U. minor and U. intermedia, differing but little in general aspect from the common sort.
Isopelis fluitans, or the floating Isopelis, is another of the curiosities of water botany. It is somewhat common in English ponds and slow streams. The blossom is inconspicuous, having no petals; the stamens are three in number, and there is but one petal.
Subularia aquatica is one of the few aquatic plants furnished by the great family of crossworts, or plants of the cabbage and wall-flower kind. Its common name is awl-wort, and suggested by the awl-like foliage which it produces under water. It is to be found only in clear mountain lakes, for it is a true aquatic alpine, frequent only in the North of England, and in Scotland and Ireland. The aquarian who resides near any mountain lake or pool, should seek for it, and treasure it as the choicest gem in his collection. The lower leaves are curve-pointed like a cobbler’s awl, and in July it sends up a short stalk, bearing a head of snow-white four-petaled blossoms, and presents a somewhat unique example of a flower in full bloom under the water. My attention was first called to this plant by Mr. Dowden’s charming work on wild plants, called “Botany of the Bohereens.”
Ranunculus aquatalis, or the water crowfoot, must be known to everyone who has been in the habit of rambling in the country quite sober and with eyes open. It is to be found in almost every pond, and by the middle of May is in full bloom, continuing gay till far into autumn. It is a member of the buttercup family, and may be recognised as a buttercup of a snow white, with a bright yellow centre. If you step carefully to the edge of a pond or river, where this crow-foot covers the shore-water with its floating foliage and thousands of snow-flakes, you will not be in a hurry to disturb it, it is so truly beautiful. But reach forth your hand, and tenderly take up a head; and, as you draw it from its plashy bed, you will find that it is truly amphibious in structure, no part of the undergrowth being at all like that which floats above in the air and sunshine. The floating leaves are fleshy and
RANUNCULUS AQUATALIS.
neatly lobed, the lower ones are as finely cut as fennel, and from every joint numerous white rootlets will be seen protruding, on their way to find root at the bottom. This plant requires good washing in clear water before it is fixed in the tank, or it may be the means of introducing many objectionable growths. It will be best to cut away the lower portions, and root it from a good joint, allowing it just length enough to float its ark of green and white upon the surface. When you have secured as many complete plants as you require—and two strong stems will be enough for any tank—pick off a dozen or more blossom-heads, taking each at a clear joint. When the roots are planted, sprinkle the short flowering tops over the surface, and you will have at once a wide spread of snow-white flowers that will continue gay till the end of the summer, while the fixed roots will give a graceful effect to the vegetation of the mid-water.
Hydrocaris morsus ranæ, or the
HYDROCARIS
MORSUS RANÆ. common frog-bit, may be obtained of the dealers, and is common in brooks and rivers. It is a perennial, interesting in its growth, very curious when in flower, and a good maker of oxygen.
Alisma, of several species, may be obtained from brooks and rivers in plenty. It is the Water Plaintain of the old botanists, and has an ancient renown, which cannot be dealt with here. The long stems and lanceolate leaves of this genera give a pleasing variety to the vegetation of the tank.
Lemna.—The four English species may be used to advantage. If the whole of the surface be covered with the pretty grass-green fronds of this very common plant, the effect is good, and it gives a salutary shade to the finny creatures. A single frond thrown in will soon spread and cover the tank in time, and its growth cannot be contemplated without pleasure. L. triscula is a very pretty kind, common in the neighbourhood of London.
The sweet-scented Rush, members of the Alisma tribe, the noble Sagittaria of six species, the Hornwort (Ceratophyllum) of two species, and for more delicate purposes, Chara and Nitella may be recommended as suitable additions to the botanical department of the Aquarium.