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 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.
[Illustration: 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 by
a piece of bass, and dropped in to fix itself where wanted, without in
any way disturbing the tank.
[Illustration: VALLISNERIA SPIRALIS.]
_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.
[Illustration: 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.
[Illustration: 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."
[Illustration: RANUNCULUS AQUATALIS.]
_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 crowfoot 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
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.
[Illustration: HYDROCARIS MORSUS RANÆ.]
_Hydrocaris morsus ranæ_, or the 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.