ON THE NATURE AND PROPERTIES OF THE CLOVER FAMILY OF PLANTS.
Clovers are admitted by all to be such important adjuncts to the fodder
plants of the farm as to render a scientific and practical treatise upon
them and their allies a matter not only of interest, but of general
agricultural utility; for, if we except the grasses, perhaps no natural
order of plants is of greater value to the farmer than that to which the
clovers belong; for, though they differ in every point of their
structure, yet in their farm products they offer an interesting
analogy. Thus, whilst in the Graminaceous plants we have cereal or
corn-seed products, and meadow and pasture herbs, in the Leguminous
plants we have a seed-producing group termed pulse, and a herb-growing
green-food or fodder series. On either hand, in both groups, there are
differently-cultivated forms; for, while the grass-cereals are wholly
the result of arable culture, the fodder grasses are for the most part
grown under conditions distinguished by the farmer as pasture. So of
leguminous plants, pulse, such as peas and beans, belongs exclusively to
the arable part of the farm; but the fodder kinds, as clover, either mix
with the grass of the meadow, or are grown by themselves or with
grasses in shifting green crops: indeed, it is by reason of clovers
eking out grass, or being used as pasturage, that they have come to be
designated “artificial grasses.”
The tribe of plants under review forms an exceedingly natural group,
which has been named _Papilionaceæ_, from the fancied resemblance in the
arrangement of its flowers to the form and varied colouring of
butterflies: by others it is designated _Leguminosæ_ from the two-valved
seed-pod, which by the botanist is termed a _legume_,—most perfect
examples of which are seen in the fruits of our more ordinary pea and
bean.
Though the flowers of the group are infinitely varied in size and in
colour, yet they afford most permanent characters in their irregular
petals, which, after all, have the same parts in the variously coloured
and showy sweet-pea as in the most minute clover; so that, once examine
the pea or bean, and the significance of the name of the order depending
upon the flowers, will be easily understood. Again, varied as is the
seed-pod, yet a little examination will show that its type is simple,
there being no structural difference between the straight legume of the
pea and the spirally-twisted one of the lucerne and medicks, or the
many-seeded smooth pod of the common broom and the single-seeded
wrinkled pod of the sainfoin.
The seeds, again, may vary in colour; some, like those of the
scarlet-runner, are curious as affording an infinite variety of
self-colours for their different sorts, from pure white to absolute
black; or these may be so pencilled as to make a _testa_ or
seed-covering as variously mottled as are the eggs of some of our birds.
Yet, whether rounded as in the pea, flat as in the bean, lenticular as
in the lentil, or kidney-shaped as in the clovers, they are all readily
referred to one group by the flat, oval eye (_hilum_ of the botanist),
and the fact of their ready capability of separating into two valves
(_cotyledons_), so observable in our split peas and beans.
But of all the varieties in their parts presented by the pea-flowered
tribe of plants,—if we except the fact that some are larger trees, as
the locust tree, ebony, laburnum, &c., whilst some are among our
smallest plants, as clovers and medicks,—the principal differences will
be found in the foliage. The grass vetchling, for example, is so named
from its leaves being not unlike those of grasses, while the yellow
vetchling, in its mature state, has the whole leaf converted into a
tendril and the appendages at the bases of the leaves (_stipules_) are
so enlarged as to be often mistaken for leaves: in another of the
vetchlings, the everlasting sweet-pea, we find that, as so much of the
leaf is converted into tendrils to enable this handsome plant to climb
over the hedges and thickets, the stem is made four-winged with
leaf-matter, to ensure the due performance of the leaf function. Now
parts called stipules are present in this whole tribe, and, like all
other parts of these plants, they vary in form, size, and markings, and
hence afford important aid in the discrimination of species. Again, the
old furze-bush will have its leaves converted into spines, though the
seedling started with a trifoliate leaf. Points like these, however,
though most interesting to the student of vegetable physiology, are
beyond the scope of the present work.
Like every other point connected with this interesting natural order of
plants, their uses and properties are greatly varied, and perhaps
variable. The Sennas are renowned for their medicinal properties, being
in some kinds aromatic and purgative. A powerful aroma is given off from
the Melilots, similar to that of the well-known sweet vernal grass
(_Anthoxanthum odoratum_), on which account it has been recommended to
mix a little of their seeds with clovers, or to cultivate separate
patches of either the white or the yellow Melilot to place here and
there, sandwich-wise, in the clover hay-rick.
In speaking of this matter of flavour in food for cattle, we may here
mention that the seed of one of this order, which is now being
extensively employed for its flavouring principle, is the Fœnugræc
(_Trigonella fœnum-græcum_), which was formerly used in large quantities
by horse and cattle doctors as an ingredient in drenches or drinks for
horses, cows, and pigs. Latterly, however, it has been still more
largely employed as a flavouring matter in the different kinds of
“Cattle Feeds.”[5]
[5] We have cultivated these seeds in England, and found them to ripen
very well, and if the flavouring of food be correct in principle, the
seeds might readily be ground with feeding stuffs, while the dried plant
could be mixed with hay and straw in chaff.
Now, whether medicinal properties reside as a rule in all of the order,
it would perhaps be difficult to determine; but, as we sometimes find
that certain clover crops are accused of causing “scouring,” there is
perhaps reason to conclude this, but that its amount varies according to
season, soil, and cultivation.